See tutors' answers!

Algebra ->  Tutoring on algebra.com -> See tutors' answers!      Log On


   
By Tutor
 | By Problem Number | 

Tutor:
New! Get regular updates about newly solved problems via algebra.com's RSS system.

Recent problems solved by 'drj'

drj answered: 1377 problems
Jump to solutions: 0..29 , 30..59 , 60..89 , 90..119 , 120..149 , 150..179 , 180..209 , 210..239 , 240..269 , 270..299 , 300..329 , 330..359 , 360..389 , 390..419 , 420..449 , 450..479 , 480..509 , 510..539 , 540..569 , 570..599 , 600..629 , 630..659 , 660..689 , 690..719 , 720..749 , 750..779 , 780..809 , 810..839 , 840..869 , 870..899 , 900..929 , 930..959 , 960..989 , 990..1019 , 1020..1049 , 1050..1079 , 1080..1109 , 1110..1139 , 1140..1169 , 1170..1199 , 1200..1229 , 1230..1259 , 1260..1289 , 1290..1319 , 1320..1349 , 1350..1379, >>Next

Age_Word_Problems/226272: If Kevin is 5 years older than Bob and in 3 years time he will be twice his age.
How old is Kevin and Bob now?
1 solutions

Answer 168537 by drj(1380) About Me  on 2009-10-13 21:43:54 (Show Source):
You can put this solution on YOUR website!
If Kevin is 5 years older than Bob and in 3 years time he will be twice his age.
How old is Kevin and Bob now?

Step 1. Let x be the age of Bob.

Step 2. Let x+5 be the age of Kevin since he's 5 years older than Bob

Step 3. Let x+3 be the age of Bob in 3 years.

Step 4. Let x+5+3=x+8 be the age of Kevin in three years.

Step 5. Then, x+8=2(x+3) since in three years time Kevin will be twice Bob's age.

Step 6. Solving the equation in Step 5 leads to the following steps

x%2B8=2x%2B6

Subtract 6+x from both sides of the equation

x%2B8-%286%2Bx%29=2x%2B6-%286%2Bx%29

x%2B8-6-x=2x%2B6-6-x

2=x and x%2B5=7. In three years 7+3=2(2+3) or 10=10 as a check in three years time Kevin is twice as old as Bob.

Step 7. ANSWER: The age of Bob is 2 and the age of Kevin is 7.


I hope the above steps were helpful.

For free Step-By-Step Videos on Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra or for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J

drjctu@gmail.com

http://www.FreedomUniversity.TV
http://www.Facebook.com/FreedomUniversity.TV
http://www.Twitter.com/FreedomUTV


Numbers_Word_Problems/226269: the second of two numbers is 4 times the first. their sum is 50. find the number
i dont understand the question at alllll. :(
1 solutions

Answer 168536 by drj(1380) About Me  on 2009-10-13 21:36:38 (Show Source):
You can put this solution on YOUR website!
The second of two numbers is 4 times the first. Their sum is 50. Find the number.

Step 1. Let x be the first number.

Step 2. Let 4x be the second number since it is 4 times the first.

Step 3. Let x+4x=50 be the sum of the two numbers and is given as 50.

Step 4. Solving the equation in Step 3 leads to the following steps.

5x=50

Divide by 5 to both sides of the equation to get x

5x%2F5=50%2F5

x=10 and 4x=40. Also, the sum of 10 and 40 is 50 as a check of the solution.

Step 5. ANSWER: The numbers are 10 and 40.


I hope the above steps were helpful.

For free Step-By-Step Videos on Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra or for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J

drjctu@gmail.com

http://www.FreedomUniversity.TV
http://www.Facebook.com/FreedomUniversity.TV
http://www.Twitter.com/FreedomUTV


Linear-equations/226263: 2x=x+4
1 solutions

Answer 168535 by drj(1380) About Me  on 2009-10-13 21:32:09 (Show Source):
You can put this solution on YOUR website!
2x=x%2B4

Step 1. Subtract x from both sides of the equation

2x-x=x%2B4-x

x=4

Step 2. Check solution x=4 with original equation 2x=x%2B4

2%2A4=4%2B4

8=8 which is a true statement

Step 3. ANSWER: The solution is x=4


I hope the above steps were helpful.

For free Step-By-Step Videos on Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra or for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J

drjctu@gmail.com

http://www.FreedomUniversity.TV
http://www.Facebook.com/FreedomUniversity.TV
http://www.Twitter.com/FreedomUTV


Numbers_Word_Problems/226268: The sum of four consecutive odd integers is 216 . Find the four integers
1 solutions

Answer 168534 by drj(1380) About Me  on 2009-10-13 21:29:34 (Show Source):
You can put this solution on YOUR website!
The sum of four consecutive odd integers is 216 . Find the four integers

Step 1. Let n be the first odd integer.

Step 2. Let n+2, n+4, and n+6 be the next three consecutive odd integers

Step 3. Then, n+n+2+n+4+n+6=216 since the sum of the four consecutive odd integers is 216.

Step 4. Solving the equation in Step 4 yields the following steps

Solved by pluggable solver: EXPLAIN simplification of an expression
Your Result:


YOUR ANSWER


  • Here's what you tried:
  • This is an equation! Solutions: n=51.
  • Graphical form: Equation n%2Bn%2B2%2Bn%2B4%2Bn%2B6=216 was fully solved.
  • Text form: n+n+2+n+4+n+6=216 simplifies to 0=0
  • Cartoon (animation) form: simplify_cartoon%28+n%2Bn%2B2%2Bn%2B4%2Bn%2B6=216+%29
    For tutors: simplify_cartoon( n+n+2+n+4+n+6=216 )
  • If you have a website, here's a link to this solution.

DETAILED EXPLANATION


Look at n%2Bn%2Bhighlight_red%28+2+%29%2Bn%2Bhighlight_red%28+4+%29%2Bn%2Bhighlight_red%28+6+%29=216.
Added fractions or integers together
It becomes n%2Bn%2Bhighlight_green%28+12+%29%2Bn%2Bn=216.

Look at n%2Bn%2Bhighlight_red%28+12+%29%2Bn%2Bn=216.
Moved 12 to the right of expression
It becomes n%2Bn%2Bn%2Bn%2Bhighlight_green%28+12+%29=216.

Look at .
Eliminated similar terms highlight_red%28+n+%29,highlight_red%28+n+%29,highlight_red%28+n+%29,highlight_red%28+n+%29 replacing them with highlight_green%28+%281%2B1%2B1%2B1%29%2An+%29
It becomes highlight_green%28+%281%2B1%2B1%2B1%29%2An+%29%2B12=216.

Look at .
Added fractions or integers together
It becomes %28highlight_green%28+4+%29%29%2An%2B12=216.

Look at highlight_red%28+%28highlight_red%28+4+%29%29%2An+%29%2B12=216.
Remove unneeded parentheses around factor highlight_red%28+4+%29
It becomes highlight_green%28+4+%29%2An%2B12=216.

Look at 4%2An%2B12=highlight_red%28+216+%29.
Moved these terms to the left highlight_green%28+-216+%29
It becomes 4%2An%2B12-highlight_green%28+216+%29=0.

Look at 4%2An%2Bhighlight_red%28+12+%29-highlight_red%28+216+%29=0.
Added fractions or integers together
It becomes 4%2An%2Bhighlight_green%28+-204+%29=0.

Look at 4%2An%2Bhighlight_red%28+-204+%29=0.
Removed extra sign in front of -204
It becomes 4%2An-highlight_green%28+204+%29=0.

Look at highlight_red%28+4%2An-204+%29=0.
Solved linear equation highlight_red%28+4%2An-204=0+%29 equivalent to 4*n-204 =0
It becomes highlight_green%28+0+%29=0.
Result: 0=0
This is an equation! Solutions: n=51.

Universal Simplifier and Solver


Done!



With n=51, then n+2=53, n+4=55, and n+6=57. Also 51+53+55+57=216 as a check...

Step 5. The four consecutive odd integers are 51, 53, 55, and 57


I hope the above steps were helpful.

For free Step-By-Step Videos on Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra or for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J

drjctu@gmail.com

http://www.FreedomUniversity.TV
http://www.Facebook.com/FreedomUniversity.TV
http://www.Twitter.com/FreedomUTV


Expressions-with-variables/226250: Set up a system of two equations with two variables to solve this problem. The three angles in a triangle always add up to 180 degrees. If one angle in a triangle is 132 degrees and the second is 5 times the third, what are the three angles?
1 solutions

Answer 168533 by drj(1380) About Me  on 2009-10-13 21:24:50 (Show Source):
You can put this solution on YOUR website!
Set up a system of two equations with two variables to solve this problem. The three angles in a triangle always add up to 180 degrees. If one angle in a triangle is 132 degrees and the second is 5 times the third, what are the three angles?

Step 1. Let x be the third angle.

Step 2. Let y=5x since the second is 5 times the third.

Step 3. Let x+y+132=180 since all three angles add up to 180 degrees. We can rewrite this after subtracting 132 from both side of the equation as

x%2By%2B132-132=180-132

x%2By=48

Step 4. The system of equations are

y=5x

x%2By=48

Step 5. Substitute y=5x into x%2By=48 to get x%2B5x=48}. Then

6x=48

Divide by 6 to both sides of the equation

6x%2F6=48%2F6

x=8 and y=5x=40. Also 132+8+40=180...as a check.

Step 6. ANSWER: The angles are 132, 8, and 40 degrees.


I hope the above steps were helpful.

For free Step-By-Step Videos on Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra or for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J

drjctu@gmail.com

http://www.FreedomUniversity.TV
http://www.Facebook.com/FreedomUniversity.TV
http://www.Twitter.com/FreedomUTV


Linear_Equations_And_Systems_Word_Problems/226249: The perimeter of a rectangle is 126 cm. The rectangle is twice as long as it is wide. What are its dimensions?
1 solutions

Answer 168529 by drj(1380) About Me  on 2009-10-13 21:14:44 (Show Source):
You can put this solution on YOUR website!
The perimeter of a rectangle is 126 cm. The rectangle is twice as long as it is wide. What are its dimensions?

Step 1. The perimeter P means adding up all the four sides of a rectangle.

Step 2. Let w be the width.

Step 3. Let 2w be the length

Step 4. Then, P=w+w+2w+2w=126.

Step 5. Solving yields the following steps

Solved by pluggable solver: EXPLAIN simplification of an expression
Your Result:


YOUR ANSWER


  • Here's what you tried:
  • This is an equation! Solutions: w=21.
  • Graphical form: Equation w%2Bw%2B2w%2B2w=126 was fully solved.
  • Text form: w+w+2w+2w=126 simplifies to 0=0
  • Cartoon (animation) form: simplify_cartoon%28+w%2Bw%2B2w%2B2w=126+%29
    For tutors: simplify_cartoon( w+w+2w+2w=126 )
  • If you have a website, here's a link to this solution.

DETAILED EXPLANATION


Look at .
Eliminated similar terms highlight_red%28+w+%29,highlight_red%28+w+%29,highlight_red%28+2%2Aw+%29,highlight_red%28+2%2Aw+%29 replacing them with highlight_green%28+%281%2B1%2B2%2B2%29%2Aw+%29
It becomes highlight_green%28+%281%2B1%2B2%2B2%29%2Aw+%29=126.

Look at .
Added fractions or integers together
It becomes %28highlight_green%28+6+%29%29%2Aw=126.

Look at highlight_red%28+%28highlight_red%28+6+%29%29%2Aw+%29=126.
Remove unneeded parentheses around factor highlight_red%28+6+%29
It becomes highlight_green%28+6+%29%2Aw=126.

Look at 6%2Aw=highlight_red%28+126+%29.
Moved these terms to the left highlight_green%28+-126+%29
It becomes 6%2Aw-highlight_green%28+126+%29=0.

Look at highlight_red%28+6%2Aw-126+%29=0.
Solved linear equation highlight_red%28+6%2Aw-126=0+%29 equivalent to 6*w-126 =0
It becomes highlight_green%28+0+%29=0.
Result: 0=0
This is an equation! Solutions: w=21.

Universal Simplifier and Solver


Done!



For w=21 , then 2w=42 and P=2(21+42)=126 which is a true statement.

Step 6. ANSWER: The width is 21 cm and the length is 42 cm.

I hope the above steps were helpful.

For free Step-By-Step Videos on Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra or for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J

drjctu@gmail.com

http://www.FreedomUniversity.TV
http://www.Facebook.com/FreedomUniversity.TV
http://www.Twitter.com/FreedomUTV


Graphs/226245: Find the y- and x-intercepts for the equation.
4) f(x) = - 3 - 7x

1 solutions

Answer 168526 by drj(1380) About Me  on 2009-10-13 21:10:29 (Show Source):
You can put this solution on YOUR website!
Find the y- and x-intercepts for the equation.
4) f(x) = - 3 - 7x

Step 1. Given y=f(x)=-3-7x, then x-intercepts occur when y=0. Then 0=-3-7x leads to
Adding 7x to both sides of the equation

0%2B7x=-3-7x%2B7x

7x=-3

Divide by 7 to both sides of the equation

7x%2F7=-3%2F7

x=-3%2F7

Step 2. Given y=-3x-7, y-intercepts occur when x=0, y=-3*x-7 or y=-7.

Step 3. ANSWER: The x-intercept occurs at point (-3/7,0) and the y-intercept occurs at point(0,-7).

I hope the above steps were helpful.

For free Step-By-Step Videos on Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra or for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J





Numbers_Word_Problems/226182: the sum of three consecutive integers is -129. find the integers.
1 solutions

Answer 168508 by drj(1380) About Me  on 2009-10-13 19:52:14 (Show Source):
You can put this solution on YOUR website!
The sum of three consecutive integers is -129. Find the integers.

Step 1. Let n be the first integer.

Step 2. Let n+1 and n+2 be the next two consecutive integers.

Step 3. Then, n+n+1+n+2=-129 since the sum is -129.

Solved by pluggable solver: EXPLAIN simplification of an expression
Your Result:


YOUR ANSWER


  • Here's what you tried:
  • This is an equation! Solutions: n=-44.
  • Graphical form: Equation n%2Bn%2B1%2Bn%2B2=-129 was fully solved.
  • Text form: n+n+1+n+2=-129 simplifies to 0=0
  • Cartoon (animation) form: simplify_cartoon%28+n%2Bn%2B1%2Bn%2B2=-129+%29
    For tutors: simplify_cartoon( n+n+1+n+2=-129 )
  • If you have a website, here's a link to this solution.

DETAILED EXPLANATION


Look at n%2Bn%2Bhighlight_red%28+1+%29%2Bn%2Bhighlight_red%28+2+%29=-129.
Added fractions or integers together
It becomes n%2Bn%2Bhighlight_green%28+3+%29%2Bn=-129.

Look at n%2Bn%2Bhighlight_red%28+3+%29%2Bn=-129.
Moved 3 to the right of expression
It becomes n%2Bn%2Bn%2Bhighlight_green%28+3+%29=-129.

Look at highlight_red%28+n+%29%2Bhighlight_red%28+n+%29%2Bhighlight_red%28+n+%29%2B3=-129.
Eliminated similar terms highlight_red%28+n+%29,highlight_red%28+n+%29,highlight_red%28+n+%29 replacing them with highlight_green%28+%281%2B1%2B1%29%2An+%29
It becomes highlight_green%28+%281%2B1%2B1%29%2An+%29%2B3=-129.

Look at %28highlight_red%28+1+%29%2Bhighlight_red%28+1+%29%2Bhighlight_red%28+1+%29%29%2An%2B3=-129.
Added fractions or integers together
It becomes %28highlight_green%28+3+%29%29%2An%2B3=-129.

Look at highlight_red%28+%28highlight_red%28+3+%29%29%2An+%29%2B3=-129.
Remove unneeded parentheses around factor highlight_red%28+3+%29
It becomes highlight_green%28+3+%29%2An%2B3=-129.

Look at 3%2An%2B3=highlight_red%28+-129+%29.
Moved these terms to the left highlight_green%28+129+%29
It becomes 3%2An%2B3%2Bhighlight_green%28+129+%29=0.

Look at 3%2An%2Bhighlight_red%28+3+%29%2Bhighlight_red%28+129+%29=0.
Added fractions or integers together
It becomes 3%2An%2Bhighlight_green%28+132+%29=0.

Look at highlight_red%28+3%2An%2B132+%29=0.
Solved linear equation highlight_red%28+3%2An%2B132=0+%29 equivalent to 3*n+132 =0
It becomes highlight_green%28+0+%29=0.
Result: 0=0
This is an equation! Solutions: n=-44.

Universal Simplifier and Solver


Done!



With n=-44, n+1=-43, and n+2=-42. Not the sum of these integers is -129.

Step 4. The integers are -44, -43, and -42.

I hope the above steps were helpful.

For free Step-By-Step Videos on Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra or for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J


Human-and-algebraic-language/226119: Mary is 3 years older than her brother Tom, and Tom is 4 years older than John. Three years ago Mary was twice as old as John. How old is each now?
1 solutions

Answer 168487 by drj(1380) About Me  on 2009-10-13 18:40:38 (Show Source):
You can put this solution on YOUR website!
Mary is 3 years older than her brother Tom, and Tom is 4 years older than John. Three years ago Mary was twice as old as John. How old is each now?

Step 1. Let x be the age of John.

Step 2. Let x+4 be the age of Tom since Tom is 4 years older than John

Step 3. Let x+4+3=x+7 be the age of Mary since she is 3 years old than Tom

Step 4. Let x+4+3-3=x+4 be the age of Mary three years ago

Step 5. Let x-3 be the age of John three years ago.

Step 6. Then, x+4=2(x-3) since three years ago Mary was twice as old as John

Step 7. Solving equation in Step 6 yields the following steps

x%2B4=2x-6

Add 6-x to both sides to get numbers only on one side and the variable x on the other side.

x%2B4%2B6-x=2x-6%2B6-x

10=x John's age

Then x%2B4=14 Tom's age and x%2B4%2B3=17 Mary's age.

Check...if equation in Step 6 is true. Three years ago Mary was 14 years old which is twice the age of John who was 7 years old which satisfies Step 6.

Step 8. ANSWER: John is 10 years old, Tom is 14 years old and Mary is 17 years old.

I hope the above steps were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

Good luck in your studies!

Respectfully,
Dr J


Problems-with-consecutive-odd-even-integers/226096: Find two consecutive even integers whose sum is 117
1 solutions

Answer 168475 by drj(1380) About Me  on 2009-10-13 17:43:48 (Show Source):
You can put this solution on YOUR website!
Find two consecutive even integers whose sum is 117.

Step 1. Let n be the first even integer.

Step 2. Let n+2 be the next consecutive even integer.

Step 3. Then n+n+2=117 since two consecutive even integers whose sum is 117.

Step 4. Solving yields the following steps.



Divide by 2 to both sides of the equation

2n%2F2=115%2F2

n=17.5 but this is not an even integer.

Step 5. ANSWER: There is no solution to this problem. Note the addition of two even integers will not yield an odd integer.

I hope the above steps and explanation were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J
http://www.FreedomUniversity.TV


test/226090: Graph the line that passes through the point(-1,2)and has slope –4/3.

1 solutions

Answer 168473 by drj(1380) About Me  on 2009-10-13 17:38:31 (Show Source):
You can put this solution on YOUR website!
Graph the line that passes through the point(-1,2)and has slope –4/3.

Step 1. Starting with the (-1,2) or x=-1 and y=2, we move 3 units to the RIGHT and 4 units DOWN since the slope m=-4%2F3. This means we have another point at (-1+3,2-4) or (2, -2).

Step 3. Use the two points (-1,2) and (2,-2) to plot the line.

graph%28400%2C400%2C+-5%2C+5%2C+-5%2C+5%2C+-4x%2F3%2B2%2F3%29

I hope the above steps were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

Good luck in your studies!

Respectfully,
Dr J


test/226092: Graph y=1/2x-3 by using the slope and y-intercept.
1 solutions

Answer 168469 by drj(1380) About Me  on 2009-10-13 17:27:58 (Show Source):
You can put this solution on YOUR website!
Graph where m is the slope and b is the y-intercept when x=0 or at point (0,b). In this case, m=1%2F2 and b=-3 or y-intercept at (0,-3)

Step 2. Starting with the y-intercept at (0,-3) or x=0 and y=-3, we move two units to the right and one unit up since the slope is 1/2. This means we have another point at (0+2,-3+1) or (2, -2).

Step 3. Use the two points (0,-3) and (2,-2) to plot the line.

graph%28400%2C400%2C+-10%2C+10%2C+-10%2C+10%2C+x%2F2-3%29

I hope the above steps were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

Good luck in your studies!

Respectfully,
Dr J


Equations/226088: 6x-4= 1 How do you solve this one?
1 solutions

Answer 168465 by drj(1380) About Me  on 2009-10-13 17:21:32 (Show Source):
You can put this solution on YOUR website!
6x-4=+1 How do you solve this one?

Step 1. Add 4 to both sides of the equation

6x-4%2B4=1%2B4

6x=5

Step 2. Divide 6 to both sides of the equation

6x%2F6=5%2F6

x=5%2F6

Step 3. Check solution with original equation 6x-4=+1

6%2A%285%2F6%29-4=+1

5-4=1

1=1 which is a true statement

Step 4. ANSWER: Solution is x=5%2F6

I hope the above steps were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

Good luck in your studies!

Respectfully,
Dr J


Linear-equations/226066: 2x+4y=15

1 solutions

Answer 168462 by drj(1380) About Me  on 2009-10-13 17:17:39 (Show Source):
You can put this solution on YOUR website!
2x%2B4y=15

Step 1. I assume you want to plot this linear equation given in standard form.

Step 2. It takes two point to generate a line.

Step 3. Let x=0 then

2%2A0%2B4y=15

Divide 4 to both sides of the equation 4y%2F4=15%2F4

y=15%2F4. So one point is (0,15/4).

Step 4. Let y=0, then

2x%2B4%2A0=15

Divide 2 to both sides of the equation 2x%2F2=15%2F2

x=15%2F2. So another point is (15/2, 0).

Step 5. Use these two points (0,15/4) and (15/2,0) to plot the line.

Solved by pluggable solver: DESCRIBE a linear EQUATION: slope, intercepts, etc
Equation 2+x+%2B+4+y+=+15 describes a sloping line. For any
equation ax+by+c = 0, slope is -a%2Fb+=+-2%2F4.
  • X intercept is found by setting y to 0: ax+by=c becomes ax=c. that means that x = c/a. 15/2 = 7.5.
  • Y intercept is found by setting x to 0: the equation becomes by=c, and therefore y = c/b. Y intercept is 15/4 = 3.75.
  • Slope is -2/4 = -0.5.
  • Equation in slope-intercept form: y=-0.5*x+3.75.
graph%28+500%2C+500%2C+7.5-8%2C+7.5%2B8%2C+3.75-8%2C+3.75%2B8%2C+-0.5%2Ax%2B3.75+%29+



I hope the above steps were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

Good luck in your studies!

Respectfully,
Dr J


Quadratic_Equations/226036: Use algrebra so solve (x-1)(x+2)=18
iv tried and failed please help me :)
1 solutions

Answer 168461 by drj(1380) About Me  on 2009-10-13 17:10:34 (Show Source):
You can put this solution on YOUR website!
Use algebra so solve (x-1)(x+2)=18

Step 1. Multiply out to get rid of the parenthesis.

%28x-1%29%28x%2B2%29=x%5E2%2B2x-x-2=18

x%5E2%2Bx-2=18

Step 2. Subtract 18 from both sides of the equation

x%5E2%2Bx-2-18=18-18

x%5E2%2Bx-20=0

and x-4=0 or x=-5 and x=4

Step 4. We can also solve using the quadratic equation shown below:

x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+

where a=1, b=1 and c=-20

Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B1x%2B-20+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%281%29%5E2-4%2A1%2A-20=81.

Discriminant d=81 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-1%2B-sqrt%28+81+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%281%29%2Bsqrt%28+81+%29%29%2F2%5C1+=+4
x%5B2%5D+=+%28-%281%29-sqrt%28+81+%29%29%2F2%5C1+=+-5

Quadratic expression 1x%5E2%2B1x%2B-20 can be factored:
1x%5E2%2B1x%2B-20+=+1%28x-4%29%2A%28x--5%29
Again, the answer is: 4, -5. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B1%2Ax%2B-20+%29



...same as before.

Step 5. ANSWER: The solutions are x=-5 and x=4.

I hope the above steps were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

Good luck in your studies!

Respectfully,
Dr J


Numbers_Word_Problems/225987: the sum of two numbers is 42. If the larger number is 3 more than triple the number find both numbers
1 solutions

Answer 168433 by drj(1380) About Me  on 2009-10-13 15:21:52 (Show Source):
You can put this solution on YOUR website!
The sum of two numbers is 42. If the larger number is 3 more than triple the number find both numbers

Step 1. Let x be the larger number.

Step 2. Let 42-x be the other and smaller number.

Step 3. Then, x=3+3(42-x) where I assume you meant the larger number is 3 more than triple the smaller number.

Step 4. Solving the equation in Step 3 yields the following steps

Solved by pluggable solver: EXPLAIN simplification of an expression
Your Result:


YOUR ANSWER


  • Here's what you tried:
  • This is an equation! Solutions: x=32.25.
  • Graphical form: Equation x=3%2B3%2A%2842-x%29 was fully solved.
  • Text form: x=3+3*(42-x) simplifies to 0=0
  • Cartoon (animation) form: simplify_cartoon%28+x=3%2B3%2A%2842-x%29+%29
    For tutors: simplify_cartoon( x=3+3*(42-x) )
  • If you have a website, here's a link to this solution.

DETAILED EXPLANATION


Look at x=3%2B3%2A%28highlight_red%28+42+%29-x%29.
Moved 42 to the right of expression
It becomes x=3%2B3%2A%28-x%2Bhighlight_green%28+42+%29%29.

Look at x=highlight_red%28+3+%29%2B3%2A%28-x%2B42%29.
Moved 3 to the right of expression
It becomes x=3%2A%28-x%2B42%29%2Bhighlight_green%28+3+%29.

Look at x=highlight_red%28+3%2A%28-x%2B42%29%2B3+%29.
Moved these terms to the left highlight_green%28+-3%2A%28-x%2B42%29+%29,highlight_green%28+-3+%29
It becomes x-highlight_green%28+3%2A%28-x%2B42%29+%29-highlight_green%28+3+%29=0.

Look at x-highlight_red%28+3%2A%28-x%2B42%29+%29-3=0.
Expanded term -3 by using associative property on %28-x%2B42%29
It becomes x%2Bhighlight_green%28+3%2Ax+%29-highlight_green%28+3%2A42+%29-3=0.

Look at x%2B3%2Ax-highlight_red%28+3+%29%2Ahighlight_red%28+42+%29-3=0.
Multiplied numerator integers
It becomes x%2B3%2Ax-highlight_green%28+126+%29-3=0.

Look at x%2B3%2Ax-highlight_red%28+126+%29-highlight_red%28+3+%29=0.
Added fractions or integers together
It becomes x%2B3%2Ax%2Bhighlight_green%28+-129+%29=0.

Look at x%2B3%2Ax%2Bhighlight_red%28+-129+%29=0.
Removed extra sign in front of -129
It becomes x%2B3%2Ax-highlight_green%28+129+%29=0.

Look at highlight_red%28+x+%29%2Bhighlight_red%28+3%2Ax+%29-129=0.
Eliminated similar terms highlight_red%28+x+%29,highlight_red%28+3%2Ax+%29 replacing them with highlight_green%28+%281%2B3%29%2Ax+%29
It becomes highlight_green%28+%281%2B3%29%2Ax+%29-129=0.

Look at %28highlight_red%28+1+%29%2Bhighlight_red%28+3+%29%29%2Ax-129=0.
Added fractions or integers together
It becomes %28highlight_green%28+4+%29%29%2Ax-129=0.

Look at highlight_red%28+%28highlight_red%28+4+%29%29%2Ax+%29-129=0.
Remove unneeded parentheses around factor highlight_red%28+4+%29
It becomes highlight_green%28+4+%29%2Ax-129=0.

Look at highlight_red%28+4%2Ax-129+%29=0.
Solved linear equation highlight_red%28+4%2Ax-129=0+%29 equivalent to 4*x-129 =0
It becomes highlight_green%28+0+%29=0.
Result: 0=0
This is an equation! Solutions: x=32.25.

Universal Simplifier and Solver


Done!



Let x=32.25, then 42-32.25=9.75. Check if equation is satisfied in Step 3.

32.25=3+3*9.75 which is a true statement.

I hope the above steps were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J
http://www.FreedomUniversity.TV


real-numbers/226000: For three consecutive odd integers, the sum of the least and greatest is 146. What is the sum of all three integers?
1 solutions

Answer 168431 by drj(1380) About Me  on 2009-10-13 15:12:23 (Show Source):
You can put this solution on YOUR website!
For three consecutive odd integers, the sum of the least and greatest is 146. What is the sum of all three integers?

What is the answer?

Step 1. Let n be the first odd integer.

Step 2. Let n%2B2 and n%2B4 and be the next two consecutive integers.

Step 3. Let n%2Bn%2B4=146 since the sum of the least and greatest is 146.

Step 4. Solving the equation in Step 3 yields the following steps.

Solved by pluggable solver: EXPLAIN simplification of an expression
Your Result:


YOUR ANSWER


  • Here's what you tried:
  • This is an equation! Solutions: n=71.
  • Graphical form: Equation n%2Bn%2B4=146 was fully solved.
  • Text form: n+n+4=146 simplifies to 0=0
  • Cartoon (animation) form: simplify_cartoon%28+n%2Bn%2B4=146+%29
    For tutors: simplify_cartoon( n+n+4=146 )
  • If you have a website, here's a link to this solution.

DETAILED EXPLANATION


Look at highlight_red%28+n+%29%2Bhighlight_red%28+n+%29%2B4=146.
Eliminated similar terms highlight_red%28+n+%29,highlight_red%28+n+%29 replacing them with highlight_green%28+%281%2B1%29%2An+%29
It becomes highlight_green%28+%281%2B1%29%2An+%29%2B4=146.

Look at %28highlight_red%28+1+%29%2Bhighlight_red%28+1+%29%29%2An%2B4=146.
Added fractions or integers together
It becomes %28highlight_green%28+2+%29%29%2An%2B4=146.

Look at highlight_red%28+%28highlight_red%28+2+%29%29%2An+%29%2B4=146.
Remove unneeded parentheses around factor highlight_red%28+2+%29
It becomes highlight_green%28+2+%29%2An%2B4=146.

Look at 2%2An%2B4=highlight_red%28+146+%29.
Moved these terms to the left highlight_green%28+-146+%29
It becomes 2%2An%2B4-highlight_green%28+146+%29=0.

Look at 2%2An%2Bhighlight_red%28+4+%29-highlight_red%28+146+%29=0.
Added fractions or integers together
It becomes 2%2An%2Bhighlight_green%28+-142+%29=0.

Look at 2%2An%2Bhighlight_red%28+-142+%29=0.
Removed extra sign in front of -142
It becomes 2%2An-highlight_green%28+142+%29=0.

Look at highlight_red%28+2%2An-142+%29=0.
Solved linear equation highlight_red%28+2%2An-142=0+%29 equivalent to 2*n-142 =0
It becomes highlight_green%28+0+%29=0.
Result: 0=0
This is an equation! Solutions: n=71.

Universal Simplifier and Solver


Done!



With n=71, then n+2=73 and n+4=75 where the sum of the least and largest number is 146. The sum is 71+73+75=219

Step 8. ANSWER: The sum of the numbers is 219.

I hope the above steps were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J
http://www.FreedomUniversity.TV






Expressions-with-variables/225995: The shorter leg of a right triangle is 20 yards. If the hypotenuse is 29 yards, how long is the other leg?
1 solutions

Answer 168430 by drj(1380) About Me  on 2009-10-13 15:05:09 (Show Source):
You can put this solution on YOUR website!
The shorter leg of a right triangle is 20 yards. If the hypotenuse is 29 yards, how long is the other leg?

Step 1. Use the Pythagorean Theorem which states that the sum of the squares of the legs (given legs a and) is equal to the square of the hypotenuse c.

a%5E2%2Bb%5E2=c%5E2

Step 2. Let a=20 and c=29, we can find the other leg b as follows

20%5E2%2Bb%5E2=29%5E2

Subtract 20%5E2 from both sides of the equation

b%5E2=29%5E2-20%5E2=841-400

b%5E2=441

Take the square root of b to both sides of the equation

b=sqrt%28441%29=21

Step 3. ANSWER. The length of the other leg is 21 yards.

I hope the above steps were helpful.

For free Step-By-Step Videos on Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra or for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J

drjctu@gmail.com

http://www.FreedomUniversity.TV
http://www.Facebook.com/FreedomUniversity.TV
http://www.Twitter.com/FreedomUTV


Numbers_Word_Problems/225986: the difference between two numbers is 22. If the larger number is 4 more than twice the smaller. Find the numbers

1 solutions

Answer 168426 by drj(1380) About Me  on 2009-10-13 14:58:18 (Show Source):
You can put this solution on YOUR website!
The difference between two numbers is 22. If the larger number is 4 more than twice the smaller. Find the numbers

Step 1. Let x be one number

Step 2. Let 22+x be the larger number and since the difference between the two numbers is 22.

Step 3. Let 2x be twice the smaller.

Step 4. 22+x=4+2x since the larger number is 4 more than twice the smaller.

Step 5. Solving the equation in Step 4 leads to the following steps.

Solved by pluggable solver: EXPLAIN simplification of an expression
Your Result:


YOUR ANSWER


  • Here's what you tried:
  • This is an equation! Solutions: x=18.
  • Graphical form: Equation 22%2Bx=4%2B2x was fully solved.
  • Text form: 22+x=4+2x simplifies to 0=0
  • Cartoon (animation) form: simplify_cartoon%28+22%2Bx=4%2B2x+%29
    For tutors: simplify_cartoon( 22+x=4+2x )
  • If you have a website, here's a link to this solution.

DETAILED EXPLANATION


Look at highlight_red%28+22+%29%2Bx=4%2B2x.
Moved 22 to the right of expression
It becomes x%2Bhighlight_green%28+22+%29=4%2B2x.

Look at x%2B22=highlight_red%28+4+%29%2B2%2Ax.
Moved 4 to the right of expression
It becomes x%2B22=2%2Ax%2Bhighlight_green%28+4+%29.

Look at x%2B22=highlight_red%28+2%2Ax%2B4+%29.
Moved these terms to the left highlight_green%28+-2%2Ax+%29,highlight_green%28+-4+%29
It becomes x%2B22-highlight_green%28+2%2Ax+%29-highlight_green%28+4+%29=0.

Look at x%2Bhighlight_red%28+22+%29-2%2Ax-highlight_red%28+4+%29=0.
Added fractions or integers together
It becomes x%2Bhighlight_green%28+18+%29-2%2Ax=0.

Look at x%2Bhighlight_red%28+18+%29-2%2Ax=0.
Moved 18 to the right of expression
It becomes x-2%2Ax%2Bhighlight_green%28+18+%29=0.

Look at highlight_red%28+x+%29-highlight_red%28+2%2Ax+%29%2B18=0.
Eliminated similar terms highlight_red%28+x+%29,highlight_red%28+-2%2Ax+%29 replacing them with highlight_green%28+%281-2%29%2Ax+%29
It becomes highlight_green%28+%281-2%29%2Ax+%29%2B18=0.

Look at %28highlight_red%28+1+%29-highlight_red%28+2+%29%29%2Ax%2B18=0.
Added fractions or integers together
It becomes %28highlight_green%28+-1+%29%29%2Ax%2B18=0.

Look at %28highlight_red%28+-1+%29%29%2Ax%2B18=0.
Removed extra sign in front of -1
It becomes %28-highlight_green%28+1+%29%29%2Ax%2B18=0.

Look at highlight_red%28+%28-highlight_red%28+1+%29%29%2Ax+%29%2B18=0.
Remove unneeded parentheses around factor highlight_red%28+1+%29
It becomes -highlight_green%28+1+%29%2Ax%2B18=0.

Look at -highlight_red%28+1+%29%2Ax%2B18=0.
Remove extraneous '1' from product highlight_red%28+1+%29
It becomes -x%2B18=0.

Look at highlight_red%28+-x%2B18+%29=0.
Solved linear equation highlight_red%28+-x%2B18=0+%29 equivalent to -x+18 =0
It becomes highlight_green%28+0+%29=0.
Result: 0=0
This is an equation! Solutions: x=18.

Universal Simplifier and Solver


Done!



With x=18, then 22+x=40

Check with equation four 22+x=4+2x or 40=4+2*18 or 40=40 which is a true statement.

Step 6. Then numbers are 18 and 40


I hope the above steps were helpful.

For free Step-By-Step Videos on Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra or for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J

drjctu@gmail.com

http://www.FreedomUniversity.TV
http://www.Facebook.com/FreedomUniversity.TV
http://www.Twitter.com/FreedomUTV


Linear-systems/225910: -3=-4y+1
1 solutions

Answer 168425 by drj(1380) About Me  on 2009-10-13 14:51:15 (Show Source):
You can put this solution on YOUR website!
-3=-4y%2B1

Step 1. Subtract 1 from both sides of the equation

-3-1=-4y%2B1-1

-4=-4y

Step 2. Divide by -4 to both sides of the equation

-4%2F-4=-4y%2F-4

y=1

Step 3. ANSWER: The solution is y=1

I hope the above steps were helpful.

For free Step-By-Step Videos on Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra or for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J

drjctu@gmail.com

http://www.FreedomUniversity.TV
http://www.Facebook.com/FreedomUniversity.TV
http://www.Twitter.com/FreedomUTV


Quadratic_Equations/225944: THE PERIMETER IS 1280, THE WIDTH IS 90 LESS THAN THE LENGTH, WHAT IS THE LENGTH AND WIDTH?
1 solutions

Answer 168423 by drj(1380) About Me  on 2009-10-13 14:47:21 (Show Source):
You can put this solution on YOUR website!
THE PERIMETER IS 1280, THE WIDTH IS 90 LESS THAN THE LENGTH, WHAT IS THE LENGTH AND WIDTH?

Step 1. The perimeter P means adding up all the four sides of a rectangle.

Step 2. Let w be the width.

Step 3. Let w+90 be the length since the width is 90 less than the length

Step 4. Then, P=w+w+w+90+w+90=1280.

Step 5. Solving yields the following steps

Solved by pluggable solver: EXPLAIN simplification of an expression
Your Result:


YOUR ANSWER


  • Here's what you tried:
  • This is an equation! Solutions: w=275.
  • Graphical form: Equation w%2Bw%2Bw%2B90%2Bw%2B90=1280 was fully solved.
  • Text form: w+w+w+90+w+90=1280 simplifies to 0=0
  • Cartoon (animation) form: simplify_cartoon%28+w%2Bw%2Bw%2B90%2Bw%2B90=1280+%29
    For tutors: simplify_cartoon( w+w+w+90+w+90=1280 )
  • If you have a website, here's a link to this solution.

DETAILED EXPLANATION


Look at w%2Bw%2Bw%2Bhighlight_red%28+90+%29%2Bw%2Bhighlight_red%28+90+%29=1280.
Added fractions or integers together
It becomes w%2Bw%2Bw%2Bhighlight_green%28+180+%29%2Bw=1280.

Look at w%2Bw%2Bw%2Bhighlight_red%28+180+%29%2Bw=1280.
Moved 180 to the right of expression
It becomes w%2Bw%2Bw%2Bw%2Bhighlight_green%28+180+%29=1280.

Look at .
Eliminated similar terms highlight_red%28+w+%29,highlight_red%28+w+%29,highlight_red%28+w+%29,highlight_red%28+w+%29 replacing them with highlight_green%28+%281%2B1%2B1%2B1%29%2Aw+%29
It becomes highlight_green%28+%281%2B1%2B1%2B1%29%2Aw+%29%2B180=1280.

Look at .
Added fractions or integers together
It becomes %28highlight_green%28+4+%29%29%2Aw%2B180=1280.

Look at highlight_red%28+%28highlight_red%28+4+%29%29%2Aw+%29%2B180=1280.
Remove unneeded parentheses around factor highlight_red%28+4+%29
It becomes highlight_green%28+4+%29%2Aw%2B180=1280.

Look at 4%2Aw%2B180=highlight_red%28+1280+%29.
Moved these terms to the left highlight_green%28+-1280+%29
It becomes 4%2Aw%2B180-highlight_green%28+1280+%29=0.

Look at 4%2Aw%2Bhighlight_red%28+180+%29-highlight_red%28+1280+%29=0.
Added fractions or integers together
It becomes 4%2Aw%2Bhighlight_green%28+-1100+%29=0.

Look at 4%2Aw%2Bhighlight_red%28+-1100+%29=0.
Removed extra sign in front of -1100
It becomes 4%2Aw-highlight_green%28+1100+%29=0.

Look at highlight_red%28+4%2Aw-1100+%29=0.
Solved linear equation highlight_red%28+4%2Aw-1100=0+%29 equivalent to 4*w-1100 =0
It becomes highlight_green%28+0+%29=0.
Result: 0=0
This is an equation! Solutions: w=275.

Universal Simplifier and Solver


Done!



For w=275 , then w+90=365 and P=2(275+365)=1280 which is a true statement.

Step 6. ANSWER: The length is 365 and the width is 275

I hope the above steps were helpful.

For free Step-By-Step Videos on Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra or for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J

drjctu@gmail.com

http://www.FreedomUniversity.TV
http://www.Facebook.com/FreedomUniversity.TV
http://www.Twitter.com/FreedomUTV


Linear-systems/225957: Solve by method of elimination: 2x +3y =10
-3x+y =18
1 solutions

Answer 168420 by drj(1380) About Me  on 2009-10-13 14:39:04 (Show Source):
You can put this solution on YOUR website!
Solve by method of elimination:

2x +3y =10 Equation A
-3x+y =18 Equation B

Step 1. Multiply Equation B by 3 and subtract from Equation A to eliminate y terms

%282x%2B3y%29-%28-9x%2B3y%29=10-3%2A18

2x%2B9x%2B3y-3y=-44

11x=-44

Step 2. Divide by 11 to both sides of the equation

11x%2F11=-44%2F11

x=-4

Step 3. Substitute x=-4in Equation A 2x+%2B3y+=10 to find y

2%2A%28-4%29%2B3y=10

-8%2B3y=10

Step 4. Add 8 to both sides of the equation to find y

-8%2B3y%2B8=10%2B8

3y=18

Step 5. Divide by 3 to both sides of the equation

3y%2F3=18%2F3

y=6

Step 6. Check solution of x=-4 and y=6 with Equation B -3x%2By+=18

-3%2A%28-4%29%2B6=18

12%2B6=18

18=18 which is a true statement.

Step 7. ANSWER: The solution is (-4,6) or x=-4 and y=6 for the linear system of equations.

I hope the above steps and explanation were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J
http://www.FreedomUniversity.TV







Surface-area/225978: find the area of a rectangle with base of 2yd and height 5ft
1 solutions

Answer 168415 by drj(1380) About Me  on 2009-10-13 14:27:28 (Show Source):
You can put this solution on YOUR website!
Find the area of a rectangle with base of 2yd and height 5ft

Step 1. Area A=b*h where b is the base and h is the height

Step 2. 1 yard = 3 feet or 2 yards = 6 feet.

Step 3. A=6*5=30 square feet

Step 4. ANSWER: The area is 30 square feet.

I hope the above steps and explanation were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J
http://www.FreedomUniversity.TV


Equations/225967: solve x^4 + 6x^2 - 27 = 0
1 solutions

Answer 168413 by drj(1380) About Me  on 2009-10-13 14:18:30 (Show Source):
You can put this solution on YOUR website!
x%5E4+%2B+6x%5E2+-+27+=+0

Step 1. Let y=x%5E2, then x%5E4=y%5E2.

Step 2. Then,

y%5E2%2B6y-27=0

Step 3. To solve equation in Step 2, use the quadratic formula

y+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+

where a=1, b=6, and c=-27

Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ay%5E2%2Bby%2Bc=0 (in our case 1y%5E2%2B6y%2B-27+=+0) has the following solutons:

y%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%286%29%5E2-4%2A1%2A-27=144.

Discriminant d=144 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-6%2B-sqrt%28+144+%29%29%2F2%5Ca.

y%5B1%5D+=+%28-%286%29%2Bsqrt%28+144+%29%29%2F2%5C1+=+3
y%5B2%5D+=+%28-%286%29-sqrt%28+144+%29%29%2F2%5C1+=+-9

Quadratic expression 1y%5E2%2B6y%2B-27 can be factored:
1y%5E2%2B6y%2B-27+=+1%28y-3%29%2A%28y--9%29
Again, the answer is: 3, -9. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B6%2Ax%2B-27+%29



With y=3 and y=-9 or x%5E2=3 and x%5E2=-9

So x=sqrt%283%29, x=-sqrt%283%29, x=sqrt%28-9%29=3i and x=-3i where i=sqrt%28-1%29

Step 4. ANSWER: So x=sqrt%283%29, x=-sqrt%283%29, x=3i and x=-3i

I hope the above steps and explanation were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J
http://www.FreedomUniversity.TV


Rectangles/225971: Perimeter of a rectangle. The perimeter of a rectangular backyard is 6x + 6 yards. If the width is x yards, find a binomial that represents the length.
1 solutions

Answer 168409 by drj(1380) About Me  on 2009-10-13 14:08:14 (Show Source):
You can put this solution on YOUR website!
Perimeter of a rectangle. The perimeter of a rectangular backyard is 6x + 6 yards. If the width is x yards, find a binomial that represents the length.

Step 1. Perimeter P means adding up all the sides of the rectangles.

Step 2. Let L be the length and x be the width.

Step 3. Then P=x+x+L+L=2x+2L

Step 4. But P=6x+6=2x+2L. Solving for L yields the following steps:

Subtract 2x from both sides of the equation

6x%2B6-2x=2x%2B2L-2x



2x%2B3=L

Step 5. ANSWER. The length of the rectangle is L=2x%2B3

I hope the above steps and explanation were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J
http://www.FreedomUniversity.TV


test/225969: Find the equation of the line containing the point (8, –39) and parallel to the line 6x+y= -4 .

1 solutions

Answer 168407 by drj(1380) About Me  on 2009-10-13 14:01:17 (Show Source):
You can put this solution on YOUR website!
Find the equation of the line containing the point (8, –39) and parallel to the line 6x+y= -4 .

Step 1. We can find the slope by recognizing that parallel lines have the same slope. So we need to put the equation of the line in slope-intercept form given as y=mx+b where m is the slope and b is the y-intercept b when x=0 or at point (0,b).
We can transform the given equation 6x%2By=-4 by subtracting -6x from both sides of the equation

y=-6x-4

Since y=-6x-4 is in slope-intercept form given as y=mx+b where the slope m=-6 and the y-intercept b=-4 when x=0 or at point (0,b) or (0,-4).

Step 2. Now we have to find the line with slope m=-6 going through point (8,-39).

Step 3. Given two points (x1,y1) and (x2,y2), then the slope m is given as

m=%28y2-y1%29%2F%28x2-x1%29

Step 4. Let (x1,y1)=(8,-39) or x1=8 and y1=-39. Let other point be (x2,y2)=(x,y) or x2=x and y2=y.

Step 5. Now we're given m=-6. Substituting above values and variables in the slope equation m yields the following steps:

m=%28y2-y1%29%2F%28x2-x1%29

-6=%28y-%28-39%29%29%2F%28x-8%29=%28y%2B39%29%2F%28x-8%29

Step 6. Multiply x-8 to both sides to get rid of denominator on right side of equation.

-6%28x-8%29%2F3=y%2B39

-6x%2B48=y%2B39

Subtract 39 from both sides of the equation

-6x%2B48-39=y%2B39-39

-6x%2B9=y

Step 7. ANSWER: The equation in slope-intercept form is y=-6x%2B9


Note: the above equation can be rewritten as

6x%2By=9

And the graph is shown below which is consistent with the above steps.

Solved by pluggable solver: DESCRIBE a linear EQUATION: slope, intercepts, etc
Equation 6+x+%2B+1+y+=+9 describes a sloping line. For any
equation ax+by+c = 0, slope is -a%2Fb+=+-6%2F1.
  • X intercept is found by setting y to 0: ax+by=c becomes ax=c. that means that x = c/a. 9/6 = 1.5.
  • Y intercept is found by setting x to 0: the equation becomes by=c, and therefore y = c/b. Y intercept is 9/1 = 9.
  • Slope is -6/1 = -6.
  • Equation in slope-intercept form: y=-6*x+9.
graph%28+500%2C+500%2C+1.5-8%2C+1.5%2B8%2C+9-8%2C+9%2B8%2C+-6%2Ax%2B9+%29+



I hope the above steps and explanation were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J
http://www.FreedomUniversity.TV


test/225964: Point (1, –2) , m = –5.
1 solutions

Answer 168402 by drj(1380) About Me  on 2009-10-13 13:49:46 (Show Source):
You can put this solution on YOUR website!
Point (1, –2) , m = –5.

I assume you want to write the slope intercept form of the equation of the line through the given point (1,-2) with the given slope m=-5.

Step 1. The slope-intercept form is given as y=mx+b where m is the slope and b is the y-intercept when x=0 or at point (0,b).

Step 2. Now we have to find the line with slope m=-5 going through point (1,-2).

Step 3. Given two points (x1,y1) and (x2,y2), then the slope m is given as

m=%28y2-y1%29%2F%28x2-x1%29

Step 4. Let (x1,y1)=(1,-2) or x1=1 and y1=-2. Let other point be (x2,y2)=(x,y) or x2=x and y2=y.

Step 5. Now we're given m=-5. Substituting above values and variables in the slope equation m yields the following steps:

m=%28y2-y1%29%2F%28x2-x1%29

-5=%28y-%28-2%29%29%2F%28x-1%29=%28y%2B2%29%2F%28x-1%29

Step 6. Multiply x-1 to both sides to get rid of denominator on right side of equation.

-5%28x-1%29=y%2B2

-5x%2B5=y%2B2

Step 7. Add -2 to both sides of the equation

-5x%2B5%2B%28-2%29=y%2B2%2B%28-2%29

-5x%2B3=y

Step 7. ANSWER: The equation in slope-intercept form is y=-5x%2B3 where the slope m=7 and the y-intercept b=-5.

Note: the above equation can be rewritten in standard form as

5x%2By=%2B3

And the graph is shown below which is consistent with the above steps.

Solved by pluggable solver: DESCRIBE a linear EQUATION: slope, intercepts, etc
Equation 5+x+%2B+1+y+=+3 describes a sloping line. For any
equation ax+by+c = 0, slope is -a%2Fb+=+-5%2F1.
  • X intercept is found by setting y to 0: ax+by=c becomes ax=c. that means that x = c/a. 3/5 = 0.6.
  • Y intercept is found by setting x to 0: the equation becomes by=c, and therefore y = c/b. Y intercept is 3/1 = 3.
  • Slope is -5/1 = -5.
  • Equation in slope-intercept form: y=-5*x+3.
graph%28+500%2C+500%2C+0.6-8%2C+0.6%2B8%2C+3-8%2C+3%2B8%2C+-5%2Ax%2B3+%29+



I hope the above steps and explanation were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J
http://www.FreedomUniversity.TV


Proportions/225956: write in standard form the equation of the line with slope =-2 and passing through (4,1)
1 solutions

Answer 168398 by drj(1380) About Me  on 2009-10-13 13:43:22 (Show Source):
You can put this solution on YOUR website!
Write in standard form the equation of the line with slope =-2 and passing through (4,1)

Step 1. The slope-intercept form is given as y=mx+b where m is the slope and b is the y-intercept when x=0 or at point (0,b). Using the slope-intercept, we can translate it to the standard form given as Ax+By=C where A, B, and C are constants.

Step 2. Now we have to find the line with slope m=-2 going through point (4,1).

Step 3. Given two points (x1,y1) and (x2,y2), then the slope m is given as

m=%28y2-y1%29%2F%28x2-x1%29

Step 4. Let (x1,y1)=(4,1) or x1=4 and y1=1. Let other point be (x2,y2)=(x,y) or x2=x and y2=y.

Step 5. Now we're given m=-2. Substituting above values and variables in the slope equation m yields the following steps:

m=%28y2-y1%29%2F%28x2-x1%29

-2=%28y-1%29%2F%28x-4%29

Step 6. Multiply x-4 to both sides to get rid of denominator on right side of equation.

-2%28x-4%29=y-1

-2x%2B8=y-1

Step 7. Add 1 to both sides of the equation

-2x%2B8%2B1=y-1%2B1

-2x%2B9=y

Step 7. ANSWER: The equation in slope-intercept form is y=-2x%2B9 where the slope m=-2 and the y-intercept b=9. The above equation can be rewritten in standard form by adding 2x to both sides as 2x%2By=9.

And the graph is shown below which is consistent with the above steps.

Solved by pluggable solver: DESCRIBE a linear EQUATION: slope, intercepts, etc
Equation 2+x+%2B+1+y+=+9 describes a sloping line. For any
equation ax+by+c = 0, slope is -a%2Fb+=+-2%2F1.
  • X intercept is found by setting y to 0: ax+by=c becomes ax=c. that means that x = c/a. 9/2 = 4.5.
  • Y intercept is found by setting x to 0: the equation becomes by=c, and therefore y = c/b. Y intercept is 9/1 = 9.
  • Slope is -2/1 = -2.
  • Equation in slope-intercept form: y=-2*x+9.
graph%28+500%2C+500%2C+4.5-8%2C+4.5%2B8%2C+9-8%2C+9%2B8%2C+-2%2Ax%2B9+%29+



I hope the above steps and explanation were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J
http://www.FreedomUniversity.TV


Graphs/225884: Please help me solve using the elimination method. If the system has an infinite # of solutions, use set-builder notation to write the solution set. If the system has no solution,state this.

x-6y=7
2x-6y=2
1 solutions

Answer 168375 by drj(1380) About Me  on 2009-10-13 10:23:25 (Show Source):
You can put this solution on YOUR website!
Solve by elimination

x-6y=7 Equation A
2x-6y=2 Equation B

Step 1. Subtract Equation B from Equation A to eliminate the y-term

%28x-6y%29-%282x-6y%29=7-2

x-6y-2x%2B6y=5

-x=5

Step 2. Multiply by -1 to both sides to get x=-5

Step 3. Substitute x=-5 into Equation A x-6y=7+ to find y

-5-6y=7+

Add 5 to both sides of the equation to get numbers on one side and variable y on the other side.

-5-6y%2B5=7%2B5+

-6y=7%2B5+

-6y=12

Divide by -6 to both sides of the equation

-6y%2F-6=12%2F-6

y=-2

Step 4. Check x=-5 and y=-2 is solution to Equation B 2x-6y=2

2%2A%28-5%29-6%2A%28-2%29=2

-10%2B12=2

2=2 which is a true statement.

Step 5. ANSWER: The solution is x=-5 and y=-2 or (-5,-2) which is the intersection between these two lines or system of linear equations.

I hope the above steps were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

Good luck in your studies!

Respectfully,
Dr J





Numbers_Word_Problems/225878: The product of two positive consecutive numbers is 42. What is the larger number?
1 solutions

Answer 168371 by drj(1380) About Me  on 2009-10-13 09:42:29 (Show Source):
You can put this solution on YOUR website!
The product of two positive consecutive numbers is 42. What is the larger number?

Step 1. Let n be the smaller positive number.

Step 2. Let n+1 be the next consecutive and larger positive number.

Step 3. Then n(n+1)=42 since their product is 42.

Step 4. Subtract 42 from both sides of the equation to get a quadratic.

n%5E2%2Bn-42=0

Step 5. To solve, use the quadratic equation given below as

x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+

where a=1, b=1, and c=-42

Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation an%5E2%2Bbn%2Bc=0 (in our case 1n%5E2%2B1n%2B-42+=+0) has the following solutons:

n%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%281%29%5E2-4%2A1%2A-42=169.

Discriminant d=169 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-1%2B-sqrt%28+169+%29%29%2F2%5Ca.

n%5B1%5D+=+%28-%281%29%2Bsqrt%28+169+%29%29%2F2%5C1+=+6
n%5B2%5D+=+%28-%281%29-sqrt%28+169+%29%29%2F2%5C1+=+-7

Quadratic expression 1n%5E2%2B1n%2B-42 can be factored:
1n%5E2%2B1n%2B-42+=+1%28n-6%29%2A%28n--7%29
Again, the answer is: 6, -7. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B1%2Ax%2B-42+%29



Selecting the positive solution n=6, then n+1=7. Also note their product is 42.

Step 6. ANSWER: The larger number is 7.

I hope the above steps were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J
http://www.FreedomUniversity.TV






Exponents-negative-and-fractional/225860: Solve: %2810%29%2F%28a-7%29+=+%28-4%29%2F%28a%2B4%29
1 solutions

Answer 168368 by drj(1380) About Me  on 2009-10-13 09:37:35 (Show Source):
You can put this solution on YOUR website!
Solve: %2810%29%2F%28a-7%29+=+%28-4%29%2F%28a%2B4%29

Step 1. Multiply by (a-7)(a+4) to both sides of the equation to get rid of denominators.

%2810%29%28a-7%29%28a%2B4%29%2F%28a-7%29+=+%28-4%29%28a-7%29%28a%2B4%29%2F%28a%2B4%29

10%28a%2B4%29=-4%28a-7%29

10a%2B40=-4a%2B28

Step 2. Add 4a-40 to both sides of the equation to get numbers on one side and variables on the other side.

10a%2B40%2B4a-40=-4a%2B28%2B4a-40

14a=-12

Step 3. Divide by 14 to both sides of the equation to get a.


14a%2F14=-12%2F14

a=-12%2F14

a=-6%2F7

Step 4. Check solution with original equation %2810%29%2F%28a-7%29+=+%28-4%29%2F%28a%2B4%29 to see if it leads to a true statement.

%2810%29%2F%28-6%2F7-7%29+=+%28-4%29%2F%28-6%2F7%2B4%29

10%2F%28%28-6-49%29%2F7%29=%28-4%29%2F%28%28-6%2B28%29%2F7%29


10%2F%28-55%2F7%29=%28-4%29%2F%2822%2F7%29

-70%2F55=-28%2F22

-14%2F11=-14%2F11 which is a true statement.

Step 5. ANSWER is a=-6%2F7


I hope the above steps were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J
http://www.FreedomUniversity.TV