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KnightOwlTutor answered: 293 problems
Jump to solutions: 0..29 , 30..59 , 60..89 , 90..119 , 120..149 , 150..179 , 180..209 , 210..239 , 240..269 , 270..299, >>NextAngles/326743: the ratio of the measures of two complementary angles is 4:5.find the measures of the angles 1 solutions
Answer 233957 by KnightOwlTutor(293) on 2010-07-29 08:28:18 (Show Source):
You can put this solution on YOUR website!The definition of a complementary angles is that the sum of the angles is equal to 90. thus we have the ratio 4:5. We then set up the problem as follows 4x + 5x=90. Then you would add (4+5)x=9x 9x=90 divide both sides by 9 and x is equal to 10. Then we go back and multiply to find the value of each angle. ie
4(x)=4(10)=40 5(x)=5(10)=50. The angle values are 40 and 50.
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Linear_Algebra/194832: The first side of a triangle measures 5 in. less than the second side, the third side is 3 in. more than the first side, and the perimeter is 17 in. How long is the third side?
If s represents the length of the second side, which of the following represents the length of the third side?
s - 5
s - 2
s + 3
1 solutions
Answer 146167 by KnightOwlTutor(293) on 2009-05-05 08:36:09 (Show Source):
You can put this solution on YOUR website!Side 2=s
side 1=s-5
side 3=s-5+3=s-2
(s)+(s-5)+(s-2)=17
3s-7=17
add 7 to both sides
3s=24
divide both sides by 3
s=6
third side =6-2=4
The first side of a triangle measures 5 in. less than the second side, the third side is 3 in. more than the first side
second side of the triangle =s
first side of the triangle is =s-5
3rd side is =(s-5)+3=s-2
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Matrices-and-determiminant/175330: Cramers rule Cant find this problem here
Solve the system of equation using Cramer's Rule if it is applicable. If Cramer's Rule is not applicable, say so.
Parenthesis 2x+3y=41
2x-3y=-13
A Parenthesis is only in the beginning then the two equations top and bottom..
here are the choices I need
A. x=7,y=9 B. x=-9,y=7 C. x=-7,y=-9 D. x=9,y=7
I think it is B is that correct?
Help 1 solutions
Answer 130410 by KnightOwlTutor(293) on 2009-01-07 01:20:56 (Show Source):
You can put this solution on YOUR website!If you plug in the x and y values for b you will find it incorrect.
x=-9,y=7
2x+3y=41 -18+21=39
2x-3y=-13 -18-21=-39
2x+3y=41
2x-3y=-13
Add each column
4x+0=28
divide both sides by 4
x=7
Plug in the value of 7 for x to get the y value
14+3y=41
Subtract 14 from both sides
3y=27
divide both sides by 3
y=9
Plug in the values of x and y in the second equation
(2*7)-(3*9)=-13
-13=-13
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Rectangles/175296: This question is from textbook Geometry Connections
How do you find the area and width of a rectangle from diagonal and one side length?
This is exactly how the problem is stated in my book:
A rectangle has one side length of 11 mm and a diagonal of 61 mm. Draw a diagram of this rectangle (which I've done) and its width and area. 1 solutions
Answer 130409 by KnightOwlTutor(293) on 2009-01-07 01:11:00 (Show Source):
You can put this solution on YOUR website!A rectangle is composed of 4 right angles. With the diagonal you have created two triangles and better yet 2 right triangles. You would then use the pythagorean therom a^2+b^2=c^2
you already have the value for c=61 and a=11 all you have to do is plug in the numbers
121 +b^2=3721
subract 121 from both sides
b^2=3600
b=60
Let us doublecheck
121+3600=3721
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Inequalities/175331: I am trying to find the minimum for f(x)=5x^2-20x+3. i think to find the min. you do -b/2a. In which case i did (-)-20/2(5) and got 2. My teacher said that this answer was incorrect. If you could please tell me where i went wrong it would be much appreciated. thanks! 1 solutions
Answer 130408 by KnightOwlTutor(293) on 2009-01-07 01:02:56 (Show Source):
You can put this solution on YOUR website!You are trying to get the vertex. In order to do this you need to complete the square f(x)=5x^2-20x+3.Set f(x)=0
0=5x^2-20x+3
Subtract 3 from both sides
-3=5x^2-20x
Factor out the 5 on the right hand side of the equation
-3=5(x^2-4x
divide the 4 by 2 and then square it.
-3=5(x^2-4x+4)
since you added an additonal 20 on the right side -don't forget to multiply the 4 you just added by 5
-3+20=5(x-2)^2
17/5=(x-2)^2
take the square root of each side 17/5sq rt=x-2
sqrt85/5=x-2
add two to both sides
x=2sqrt85/5
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Average/175341: 6-3/4÷3=? & 8÷1-1/3=? please help me I'm having the hardest time trying to figure out these type of problems and fractions are my weakness. i've read many fractions problems but i still dan't get it. 1 solutions
Answer 130405 by KnightOwlTutor(293) on 2009-01-07 00:46:15 (Show Source):
You can put this solution on YOUR website!first you solve for 6-3/4 You need to find the common denominator for both numbers in this case it is four. the number 6 becomes 24/4 you haven't changed the number it is still the same quantity but you can now perform the subtraction part with the fraction.64/4-3/4=21/4 divided by 3=7/4
8 divided by 1 is still eight but we need to find a common denominator to solve the problem in this case it is 3. 24/3-1/3=23/3
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Linear-systems/175338: I am having trouble understanding, "solving systems of equations by graphing."
Ex:
x+y=6
x-y=4
Then, I started to try and solve and find the ordered pair that worked for both equations. I only got this far, then I get confused:
x+y=6
-x -x
______
y=-1x+6
x-y=4
-x -x
_______
-y=-1+4
1 solutions
Answer 130403 by KnightOwlTutor(293) on 2009-01-07 00:39:14 (Show Source):
You can put this solution on YOUR website!x+y=6
x-y=4
Add each colum and you get 2x (+y-y=0)=6+4
2x=10
divide both sides by two and x=5
if x is 5 then y must equal 1
5+1=6
5-1=4
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Money_Word_Problems/175217: Please help.
amount of an investment.
The amount of an investment of P dollars for t years at simple intrrest rate r is given by A=P + Prt.
Please help with rewriting the formula by factoring out the greatest common factor on the right side.
and
Find A if 8300 is invested for 3yrs at a simple intrest rate of 15%
A=8300 + (8300)3(.15)
A = 8300 + 3735.
A = 12035.00
(is this correct) 1 solutions
Answer 130291 by KnightOwlTutor(293) on 2009-01-06 12:07:03 (Show Source):
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Geometry_Word_Problems/175196: a rectangle is three times as long as it is wide . if its length and width are both decresed by 2cm its area is decreased by 36 cm squared . find its original dimensions 1 solutions
Answer 130268 by KnightOwlTutor(293) on 2009-01-06 07:06:46 (Show Source):
You can put this solution on YOUR website!We know that the difference between the 2 areas is 36. Therefore we are going to set up the equation of subtracting the two areas to get the original dimensions.
x=width of the original rectangle
3x=the length of the original rectangle
x-2=width of the smaller rectangle
3x-2=length of the smaller rectangle
the area of a rectangle is width X length
Area of the original rectangle-Area of smaller rectangle=36
(3x*x)-[(x-2)(3x-2)]=36
Use the foil method
3x^2-2x-6x+4
(3x*x)-[3x^2-2x-6x+4]=36
multply -1 to each term contained within the bracket.
Make sure to pay attention to the sign.
(+)(-)=(-)
(-)(-)=(+)
(3x^2-3x^2+2x+6x-4=36
Combine like terms and simplify
(2+6)x-4=36
8x-4=36
Add 4 to both sides of the equation
8x=40
divide both sides by 8
x=5
The dimensions of the original rectangle was 5,15
Let us double check our answer
the dimensions of the smaller rectangle is 3,13
(3*15)-(3*13)=36 75-39=36
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Rational-functions/174766: This question is from textbook Saxon Algebra 2
Find the inverse of
A= (matrix) -3....1
-5....5
if it exists. 1 solutions
Answer 130140 by KnightOwlTutor(293) on 2009-01-05 09:09:46 (Show Source):
You can put this solution on YOUR website!We know that the matrix has an inverse because the determinant is not equal to zero
[-3 1]
[-5 5]
[a b]
[c d]
To calculate the determinant ad-bc in this case -15+5=-10
Any Matrix inverse =1/ad-bc[d -b]
[-c a]
-1/10[5 -1]
[5 -3]
To double check multiply the matrices together and see if you come up with the identity matrix.
[-3 1]-1/10[5 -1]
[-5 5] [5 -3]
-15+5 3+3 -1/10[-10 0]
-25+25 5-15 -1/10[0 -10]
[1 0]
[0 1] is the identity matrix
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Coordinate-system/173829: Graph the line with slope -2/3 passong through the point (-5,5). I cannot do this problem. I have tried and when it comes to math I can't add 3 + 3. The negatives are the worst along with fractions. I just don't understand it.Can anybody figure this out and show me how? Ty in advance. Judy 1 solutions
Answer 128702 by KnightOwlTutor(293) on 2008-12-17 11:42:31 (Show Source):
You can put this solution on YOUR website!The general equation for a line is y=mx+c
m= slope
Replace m with -2/3 y=-2/3x +c
Plug in the value for the point
5=-2/3(-5) +c
We are trying to find the y intercept c
5=10/3+c
Subract 10/3 to both sides
15/3 -10/3= c
5/3= c
Let's double check that this is the correct linear equation
5=10/3 +5/3
Therefore the eqation is y=-2/3x+5/3
| Solved by pluggable solver: DESCRIBE a linear EQUATION: slope, intercepts, etc |
Equation describes a sloping line. For any
equation ax+by+c = 0, slope is .- X intercept is found by setting y to 0: ax+by=c becomes ax=c. that means that x = c/a. 5/2 = 2.5.
- Y intercept is found by setting x to 0: the equation becomes by=c, and therefore y = c/b. Y intercept is 5/3 = 1.66666666666667.
- Slope is -2/3 = -0.666666666666667.
- Equation in slope-intercept form: y=-0.666666666666667*x+1.66666666666667.
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Numbers_Word_Problems/173407: When two-thirds of a number is added to one-fourth of the same number, the result is 8 more than the original number. Find the number. 1 solutions
Answer 128265 by KnightOwlTutor(293) on 2008-12-15 07:35:15 (Show Source):
You can put this solution on YOUR website!The unknown number is x
The equation to solve is
2/3x+1/4x=x+8
The lcd is 12
Therefore multiply each term by 12
8x+3x=12x+96
simplfy terms
11x=12x+96
Subtract 12x from both sides
-x=96
divide both sides by -1
x=-96
Let's doublecheck our answer
(2(-96)/3} +(-96/4)=-96+8
-64-24=-88
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Quadratic_Equations/173410: This question is from textbook Introductory Algebra
Solve the equation
x(x-3) = 40 1 solutions
Answer 128260 by KnightOwlTutor(293) on 2008-12-15 07:07:28 (Show Source):
You can put this solution on YOUR website!x(x-3) = 40
Expand the equation
x^2-3X=40
subtract 40 from both sides
x^2-3X-40=0
Find possible factors for 40
(40,1) (2,20) (8,5)
We see that the 40 has a negative sign which means that one of the factors is negative.
Then we find which two factors when added together can give you -3
I can see from the list that the only possible answer is 5,8
(x-8)(x+5)=0 is the factored form of the above equation
Therefore the answers are x=8 and x=-5
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Quadratic_Equations/173413: This question is from textbook Introductory Algebra
Solve the equation by completing the square
p2 + 3p - 9 = 0 1 solutions
Answer 128258 by KnightOwlTutor(293) on 2008-12-15 07:00:48 (Show Source):
You can put this solution on YOUR website!p2 + 3p - 9 = 0.
Add 9 to both sides of the equation
p2 + 3p=9
Divide the coefficient of the p term(=3) term by 2 and square the resultant value and add to both sides of the equation
p2 +3p +(3/2)^2= 9 +(3/2)^2
This makes the quadratic equation a perfect square
(p+3/2)^2=9 +9/4
Simplify the left side of the equation
(p+3/2)^2=36/4+9/4=45/4
(p+3/2)^2=45/4
Take the square root of both sides
p+3/2= + or -3sqrt5/2
subtract 3/2 from both sides
p=-3/2+3sqrt5/2 or p=-3/2-3sqrt5/2
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Miscellaneous_Word_Problems/173046: Please help me solve this equation:
A ball is thrown upward with an initial velocity of 30 feet per second from a point that is 24
feet above the ground. The height h (in feet) of the ball at time t (in seconds) after it is
thrown is
h= -16t^2 + 30t + 24
Find the time when the ball hits the ground. 1 solutions
Answer 127896 by KnightOwlTutor(293) on 2008-12-13 05:47:11 (Show Source):
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Linear-equations/172710: Please help!!!
Natalie spends 90 minutes doing her mant and english homework. The time she spends on her math homework is a function of the time she spends on her english homework. 1 solutions
Answer 127577 by KnightOwlTutor(293) on 2008-12-11 08:22:52 (Show Source):
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