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Graphs/115679: Write the equation of the line that passes through point (6,4) with a slope of 2
1 solutions

Answer 84182 by jim_thompson5910(28504) About Me  on 2007-12-09 16:22:51 (Show Source):
You can put this solution on YOUR website!

If you want to find the equation of line with a given a slope of 2 which goes through the point (6,4), you can simply use the point-slope formula to find the equation:


---Point-Slope Formula---
y-y%5B1%5D=m%28x-x%5B1%5D%29 where m is the slope, and is the given point

So lets use the Point-Slope Formula to find the equation of the line

y-4=%282%29%28x-6%29 Plug in m=2, x%5B1%5D=6, and y%5B1%5D=4 (these values are given)


y-4=2x%2B%282%29%28-6%29 Distribute 2

y-4=2x-12 Multiply 2 and -6 to get -12

y=2x-12%2B4 Add 4 to both sides to isolate y

y=2x-8 Combine like terms -12 and 4 to get -8
------------------------------------------------------------------------------------------------------------
Answer:


So the equation of the line with a slope of 2 which goes through the point (6,4) is:

y=2x-8 which is now in y=mx%2Bb form where the slope is m=2 and the y-intercept is b=-8

Notice if we graph the equation y=2x-8 and plot the point (6,4), we get (note: if you need help with graphing, check out this solver)

Graph of y=2x-8 through the point (6,4)
and we can see that the point lies on the line. Since we know the equation has a slope of 2 and goes through the point (6,4), this verifies our answer.


Linear-equations/115665: solve the system by addition
3x - y =1
3x -y = 2
1 solutions

Answer 84178 by jim_thompson5910(28504) About Me  on 2007-12-09 15:57:43 (Show Source):
You can put this solution on YOUR website!
Solved by pluggable solver: Solving a System of Linear Equations by Elimination/Addition


Lets start with the given system of linear equations

3%2Ax-1%2Ay=1
3%2Ax-1%2Ay=2

In order to solve for one variable, we must eliminate the other variable. So if we wanted to solve for y, we would have to eliminate x (or vice versa).

So lets eliminate x. In order to do that, we need to have both x coefficients that are equal but have opposite signs (for instance 2 and -2 are equal but have opposite signs). This way they will add to zero.

So to make the x coefficients equal but opposite, we need to multiply both x coefficients by some number to get them to an equal number. So if we wanted to get 3 and 3 to some equal number, we could try to get them to the LCM.

Since the LCM of 3 and 3 is 3, we need to multiply both sides of the top equation by 1 and multiply both sides of the bottom equation by -1 like this:

1%2A%283%2Ax-1%2Ay%29=%281%29%2A1 Multiply the top equation (both sides) by 1
-1%2A%283%2Ax-1%2Ay%29=%282%29%2A-1 Multiply the bottom equation (both sides) by -1


So after multiplying we get this:
3%2Ax-1%2Ay=1
-3%2Ax%2B1%2Ay=-2

Notice how 3 and -3 and 1 and 1 add to zero (ie 3%2B-3=0 -1%2B1=0)

However 1 and -2 add to -1 (ie 1%2B-2=-1);


So we're left with

0=-1


which means no value of x or y value will satisfy the system of equations. So there are no solutions


So this system is inconsistent


Linear-equations/115661: help me find the slope of the graph of the linear function f

#42: f(2) = -3, f(-2) = 5


#44: f(-3) = -9, f(-1) = 2



#46: f(9) = -1, f(-1) = 2



#48: f(2) = 2, f(3) = 3

1 solutions

Answer 84177 by jim_thompson5910(28504) About Me  on 2007-12-09 15:56:49 (Show Source):
You can put this solution on YOUR website!
I'll do the first two to show you how to do these

#42
If we have the statement f(2)=-3, this means we have the point (2,-3). Also if we have the statement f(-2) = 5, this means we have the point (-2,5)

Now let's find the slope through (2,-3) and (-2,5)


Solved by pluggable solver: Finding the slope


Slope of the line through the points (2, -3) and (-2, 5)



m+=+%28y%5B2%5D+-+%28y%5B1%5D%29%29%2F%28x%5B2%5D+-+%28x%5B1%5D%29%29


m+=+%285+-+%28-3%29%29%2F%28-2+-+2%29


m+=+%285+%2B+3%29%2F%28-2+-+2%29


m+=+%288%29%2F%28-4%29


m+=+-2



Answer: Slope is m+=+-2









#44:
If we have the statement f(-3) = -9, this means we have the point (-3,-9). Also if we have the statement f(-1) = 2, this means we have the point (-1,2)

Now let's find the slope through (-3,-9) and (-1,2)


Solved by pluggable solver: Finding the slope


Slope of the line through the points (-3, -9) and (-1, 2)



m+=+%28y%5B2%5D+-+%28y%5B1%5D%29%29%2F%28x%5B2%5D+-+%28x%5B1%5D%29%29


m+=+%282+-+%28-9%29%29%2F%28-1+-+%28-3%29%29


m+=+%282+%2B+9%29%2F%28-1+%2B+3%29


m+=+%2811%29%2F%282%29


Answer: Slope is m+=+11%2F2



Functions/115662: find f(-3) when f(x)=2x^2-7x+8.
1 solutions

Answer 84176 by jim_thompson5910(28504) About Me  on 2007-12-09 15:52:50 (Show Source):
You can put this solution on YOUR website!

Let's evaluate f%28-3%29


f%28x%29=2x%5E2-7x%2B8 Start with the given function.


f%28-3%29=2%28-3%29%5E2-7%28-3%29%2B8 Plug in x=-3. In other words, replace each x with -3.


f%28-3%29=2%289%29-7%28-3%29%2B8 Evaluate %28-3%29%5E2 to get 9.


f%28-3%29=%2B18-7%28-3%29%2B8 Multiply 2 and 9 to get 18


f%28-3%29=%2B18%2B21%2B8 Multiply -7 and -3 to get 21


f%28-3%29=47 Now combine like terms


Polynomials-and-rational-expressions/115666: Factor completely. ax-ay+x squared -xy
1 solutions

Answer 84175 by jim_thompson5910(28504) About Me  on 2007-12-09 15:51:51 (Show Source):
You can put this solution on YOUR website!
ax-ay%2Bx%5E2-xy Start with the given expression

%28ax-ay%29%2B%28x%5E2-xy%29 Group like terms


a%28x-y%29%2Bx%28x-y%29 Factor out the GCF a out of the first group. Factor out the GCF x out of the second group


%28a%2Bx%29%28x-y%29 Since we have the common term x-y, we can combine like terms

So ax-ay%2Bx%5E2-xy factors to %28a%2Bx%29%28x-y%29


Equations/115667: rewrite the equation -8x -5y = -45 as a function of x
1 solutions

Answer 84174 by jim_thompson5910(28504) About Me  on 2007-12-09 15:49:56 (Show Source):
You can put this solution on YOUR website!
Solved by pluggable solver: Converting Linear Equations in Standard form to Slope-Intercept Form (and vice versa)


-8%2Ax-5%2Ay=-45Start with the given equation



-5%2Ay=-45%2B8%2Ax Add 8%2Ax to both sides

y=%28-1%2F5%29%28-45%2B8%2Ax%29 Multiply both sides by -1%2F5

y=%28-1%2F5%29%28-45%29%2B%281%2F5%29%28-8%29x%29 Distribute -1%2F5

y=45%2F5-%288%2F5%29x Multiply

y=%28-8%2F5%29%2Ax%2B45%2F5 Rearrange the terms

y=%28-8%2F5%29%2Ax%2B9 Reduce any fractions

So the equation is now in slope-intercept form (y=mx%2Bb) where m=-8%2F5 (the slope) and b=9 (the y-intercept)


Polynomials-and-rational-expressions/115668: Factor completely. m cubed - 9m squared n+ 18n squared m
1 solutions

Answer 84173 by jim_thompson5910(28504) About Me  on 2007-12-09 15:48:38 (Show Source):
You can put this solution on YOUR website!
m%5E3-9m%5E2n%2B18n%5E2m Start with the given expression


m%28m%5E2-9mn%2B18n%5E2%29 Factor out the GCF m


Now let's focus on the inner expression m%5E2-9mn%2B18n%5E2




Looking at m%5E2-9mn%2B18n%5E2 we can see that the first term is m%5E2 and the last term is 18n%5E2 where the coefficients are 1 and 18 respectively.

Now multiply the first coefficient 1 and the last coefficient 18 to get 18. Now what two numbers multiply to 18 and add to the middle coefficient -9? Let's list all of the factors of 18:



Factors of 18:
1,2,3,6,9,18

-1,-2,-3,-6,-9,-18 ...List the negative factors as well. This will allow us to find all possible combinations

These factors pair up and multiply to 18
1*18
2*9
3*6
(-1)*(-18)
(-2)*(-9)
(-3)*(-6)

note: remember two negative numbers multiplied together make a positive number


Now which of these pairs add to -9? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to -9

First NumberSecond NumberSum
1181+18=19
292+9=11
363+6=9
-1-18-1+(-18)=-19
-2-9-2+(-9)=-11
-3-6-3+(-6)=-9



From this list we can see that -3 and -6 add up to -9 and multiply to 18


Now looking at the expression m%5E2-9mn%2B18n%5E2, replace -9mn with -3mn%2B-6mn (notice -3mn%2B-6mn adds up to -9mn. So it is equivalent to -9mn)

m%5E2%2Bhighlight%28-3mn%2B-6mn%29%2B18n%5E2


Now let's factor m%5E2-3mn-6mn%2B18n%5E2 by grouping:


%28m%5E2-3mn%29%2B%28-6mn%2B18n%5E2%29 Group like terms


m%28m-3n%29-6n%28m-3n%29 Factor out the GCF of m out of the first group. Factor out the GCF of -6n out of the second group


%28m-6n%29%28m-3n%29 Since we have a common term of m-3n, we can combine like terms

So m%5E2-3mn-6mn%2B18n%5E2 factors to %28m-6n%29%28m-3n%29


So this also means that m%5E2-9mn%2B18n%5E2 factors to %28m-6n%29%28m-3n%29 (since m%5E2-9mn%2B18n%5E2 is equivalent to m%5E2-3mn-6mn%2B18n%5E2)


So m%5E2-9mn%2B18n%5E2 factors to %28m-6n%29%28m-3n%29


m%28m-6n%29%28m-3n%29 Now reintroduce the GCF

-------------------------------
Answer:


So m%5E3-9m%5E2n%2B18n%5E2m factors to m%28m-6n%29%28m-3n%29



Linear-equations/115675: Can someone please explain to me CLEARLY since my teacher never does step by step how to solve Linear Equations and slope intercept. I never know how to solve them and I fail all my tests and quizes. For example here is one problem from a quiz
4x+5=-12
1 solutions

Answer 84172 by jim_thompson5910(28504) About Me  on 2007-12-09 15:45:53 (Show Source):
You can put this solution on YOUR website!

4x%2B5=-12 Start with the given equation



4x=-12-5Subtract 5 from both sides


4x=-17 Combine like terms on the right side


x=%28-17%29%2F%284%29 Divide both sides by 4 to isolate x



x=-17%2F4 Reduce

--------------------------------------------------------------
Answer:
So our answer is x=-17%2F4 (which is approximately x=-4.25 in decimal form)


Polynomials-and-rational-expressions/115655: Can someone please help me with this problem. I tried to do the problem and I just keep getting very confused.
We are specifically looking for how to factor polynomials when the leading coefficient is not 1. How can we find the correct way to break up the middle term to make this come out right.
Can you please factor the polynomial
4x^2 + 4x - 99
Please tell us why and how you carry out each step of the process.
PLEASE HELP ME!!!!

1 solutions

Answer 84166 by jim_thompson5910(28504) About Me  on 2007-12-09 14:53:54 (Show Source):
You can put this solution on YOUR website!

Looking at 4x%5E2%2B4x-99 we can see that the first term is 4x%5E2 and the last term is -99 where the coefficients are 4 and -99 respectively.

Now multiply the first coefficient 4 and the last coefficient -99 to get -396. Now what two numbers multiply to -396 and add to the middle coefficient 4? Let's list all of the factors of -396:



Factors of -396:
1,2,3,4,6,9,11,12,18,22,33,36,44,66,99,132,198,396

-1,-2,-3,-4,-6,-9,-11,-12,-18,-22,-33,-36,-44,-66,-99,-132,-198,-396 ...List the negative factors as well. This will allow us to find all possible combinations

These factors pair up and multiply to -396
(1)*(-396)
(2)*(-198)
(3)*(-132)
(4)*(-99)
(6)*(-66)
(9)*(-44)
(11)*(-36)
(12)*(-33)
(18)*(-22)
(-1)*(396)
(-2)*(198)
(-3)*(132)
(-4)*(99)
(-6)*(66)
(-9)*(44)
(-11)*(36)
(-12)*(33)
(-18)*(22)

note: remember, the product of a negative and a positive number is a negative number


Now which of these pairs add to 4? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to 4

First NumberSecond NumberSum
1-3961+(-396)=-395
2-1982+(-198)=-196
3-1323+(-132)=-129
4-994+(-99)=-95
6-666+(-66)=-60
9-449+(-44)=-35
11-3611+(-36)=-25
12-3312+(-33)=-21
18-2218+(-22)=-4
-1396-1+396=395
-2198-2+198=196
-3132-3+132=129
-499-4+99=95
-666-6+66=60
-944-9+44=35
-1136-11+36=25
-1233-12+33=21
-1822-18+22=4



From this list we can see that -18 and 22 add up to 4 and multiply to -396


Now looking at the expression 4x%5E2%2B4x-99, replace 4x with -18x%2B22x (notice -18x%2B22x adds up to 4x. So it is equivalent to 4x)

4x%5E2%2Bhighlight%28-18x%2B22x%29%2B-99


Now let's factor 4x%5E2-18x%2B22x-99 by grouping:


%284x%5E2-18x%29%2B%2822x-99%29 Group like terms


2x%282x-9%29%2B11%282x-9%29 Factor out the GCF of 2x out of the first group. Factor out the GCF of 11 out of the second group


%282x%2B11%29%282x-9%29 Since we have a common term of 2x-9, we can combine like terms

So 4x%5E2-18x%2B22x-99 factors to %282x%2B11%29%282x-9%29


So this also means that 4x%5E2%2B4x-99 factors to %282x%2B11%29%282x-9%29 (since 4x%5E2%2B4x-99 is equivalent to 4x%5E2-18x%2B22x-99)

-------------------------------
Answer:

So 4x%5E2%2B4x-99 factors to %282x%2B11%29%282x-9%29


Inequalities/115653: how to solve?
-3(3X+1)<15
1 solutions

Answer 84165 by jim_thompson5910(28504) About Me  on 2007-12-09 14:50:59 (Show Source):
You can put this solution on YOUR website!

-3%283x%2B1%29%3C15 Start with the given inequality



-9x-3%3C15 Distribute


-9x%3C15%2B3Add 3 to both sides


-9x%3C18 Combine like terms on the right side


x%3E%2818%29%2F%28-9%29 Divide both sides by -9 to isolate x (note: Remember, dividing both sides by a negative number flips the inequality sign)



x%3E-2 Divide

--------------------------------------------------------------
Answer:
So our answer is x%3E-2


Divisibility_and_Prime_Numbers/115654: I need help with these math problems on least common multiple.

20. 16,18
23. 4,17
26. 15,18
27. 12,14
28. 7,13
32. 3,5,12
33. 6,16,24
34. 12,18,24
1 solutions

Answer 84164 by jim_thompson5910(28504) About Me  on 2007-12-09 14:48:16 (Show Source):
You can put this solution on YOUR website!
I'll do a few of these to show you how to do these problems.


#20
First, list the prime factorization of each number. If you need help with prime factorization, check out this solver.


16: 2*2*2*2


18: 2*3*3


Now highlight the unique factors. Remember, highlight the factors that occur most frequently


16: 2*2*2*2


18: 2*3*3


Now multiply all of the highlighted factors

2*2*2*2*3*3=144

So the LCM of 16 and 18 is 144




#23



First, list the prime factorization of each number. If you need help with prime factorization, check out this solver.


4: 2*2


17: 17


Now highlight the unique factors. Remember, highlight the factors that occur most frequently


4: 2*2


17: 17


Now multiply all of the highlighted factors

2*2*17=68

So the LCM of 4 and 17 is 68





#26



First, list the prime factorization of each number. If you need help with prime factorization, check out this solver.


15: 3*5


18: 2*3*3


Now highlight the unique factors. Remember, highlight the factors that occur most frequently


15: 3*5


18: 2*3*3


Now multiply all of the highlighted factors

2*3*3*5=90

So the LCM of 15 and 18 is 90





note: I skipped to a problem with 3 numbers

#33



First, list the prime factorization of each number. If you need help with prime factorization, check out this solver.


6: 2*3


16: 2*2*2*2


24: 2*2*2*3


Now highlight the unique factors. Remember, highlight the factors that occur most frequently


6: 2*3


16: 2*2*2*2


24: 2*2*2*3


Now multiply all of the highlighted factors

2*2*2*2*3=48

So the LCM of 6, 16, and 24 is 48




Distributive-associative-commutative-properties/115652: 3x^2 + 8x + 5 how would i factor this ?
1 solutions

Answer 84163 by jim_thompson5910(28504) About Me  on 2007-12-09 14:40:54 (Show Source):
You can put this solution on YOUR website!

Looking at 3x%5E2%2B8x%2B5 we can see that the first term is 3x%5E2 and the last term is 5 where the coefficients are 3 and 5 respectively.

Now multiply the first coefficient 3 and the last coefficient 5 to get 15. Now what two numbers multiply to 15 and add to the middle coefficient 8? Let's list all of the factors of 15:



Factors of 15:
1,3,5,15

-1,-3,-5,-15 ...List the negative factors as well. This will allow us to find all possible combinations

These factors pair up and multiply to 15
1*15
3*5
(-1)*(-15)
(-3)*(-5)

note: remember two negative numbers multiplied together make a positive number


Now which of these pairs add to 8? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to 8

First NumberSecond NumberSum
1151+15=16
353+5=8
-1-15-1+(-15)=-16
-3-5-3+(-5)=-8



From this list we can see that 3 and 5 add up to 8 and multiply to 15


Now looking at the expression 3x%5E2%2B8x%2B5, replace 8x with 3x%2B5x (notice 3x%2B5x adds up to 8x. So it is equivalent to 8x)

3x%5E2%2Bhighlight%283x%2B5x%29%2B5


Now let's factor 3x%5E2%2B3x%2B5x%2B5 by grouping:


%283x%5E2%2B3x%29%2B%285x%2B5%29 Group like terms


3x%28x%2B1%29%2B5%28x%2B1%29 Factor out the GCF of 3x out of the first group. Factor out the GCF of 5 out of the second group


%283x%2B5%29%28x%2B1%29 Since we have a common term of x%2B1, we can combine like terms

So 3x%5E2%2B3x%2B5x%2B5 factors to %283x%2B5%29%28x%2B1%29


So this also means that 3x%5E2%2B8x%2B5 factors to %283x%2B5%29%28x%2B1%29 (since 3x%5E2%2B8x%2B5 is equivalent to 3x%5E2%2B3x%2B5x%2B5)

-------------------------------
Answer:

So 3x%5E2%2B8x%2B5 factors to %283x%2B5%29%28x%2B1%29


Linear-equations/115649: how would I graph the line with a slope of 3 and passes through points (2,1) and (4,7).
1 solutions

Answer 84162 by jim_thompson5910(28504) About Me  on 2007-12-09 14:39:29 (Show Source):
You can put this solution on YOUR website!
If you only want to graph the line, simply plot the two points (2,1) and (4,7) and draw a straight line through them.



-------------------------------------------
However, if you want to find the equation of the line, then...

First lets find the slope through the points (2,1) and (4,7)

m=%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29 Start with the slope formula (note: is the first point (2,1) and is the second point (4,7))

m=%287-1%29%2F%284-2%29 Plug in y%5B2%5D=7,y%5B1%5D=1,x%5B2%5D=4,x%5B1%5D=2 (these are the coordinates of given points)

m=+6%2F2 Subtract the terms in the numerator 7-1 to get 6. Subtract the terms in the denominator 4-2 to get 2


m=3 Reduce

So the slope is
m=3

------------------------------------------------


Now let's use the point-slope formula to find the equation of the line:



------Point-Slope Formula------
y-y%5B1%5D=m%28x-x%5B1%5D%29 where m is the slope, and is one of the given points

So lets use the Point-Slope Formula to find the equation of the line

y-1=%283%29%28x-2%29 Plug in m=3, x%5B1%5D=2, and y%5B1%5D=1 (these values are given)


y-1=3x%2B%283%29%28-2%29 Distribute 3

y-1=3x-6 Multiply 3 and -2 to get -6

y=3x-6%2B1 Add 1 to both sides to isolate y

y=3x-5 Combine like terms -6 and 1 to get -5
------------------------------------------------------------------------------------------------------------
Answer:


So the equation of the line which goes through the points (2,1) and (4,7) is:y=3x-5

The equation is now in y=mx%2Bb form (which is slope-intercept form) where the slope is m=3 and the y-intercept is b=-5

Notice if we graph the equation y=3x-5 and plot the points (2,1) and (4,7), we get this: (note: if you need help with graphing, check out this solver)

Graph of y=3x-5 through the points (2,1) and (4,7)

Notice how the two points lie on the line. This graphically verifies our answer.


Signed-numbers/115646: Combine like terms. 5w – 6w
1 solutions

Answer 84159 by jim_thompson5910(28504) About Me  on 2007-12-09 14:23:05 (Show Source):
You can put this solution on YOUR website!
Since we have a common variable "w", we can simply subtract 6 from 5 to get -1. So

5w-6w=-1w

Which also looks like

5w-6w=-w notice the 1 has been removed


Equations/115640: This question is from textbook
5n-8=11n+5
1 solutions

Answer 84155 by jim_thompson5910(28504) About Me  on 2007-12-09 13:42:51 (Show Source):
You can put this solution on YOUR website!

5n-8=11n%2B5 Start with the given equation



5n=11n%2B5%2B8Add 8 to both sides


5n-11n=5%2B8 Subtract 11n from both sides


-6n=5%2B8 Combine like terms on the left side


-6n=13 Combine like terms on the right side


n=%2813%29%2F%28-6%29 Divide both sides by -6 to isolate n



n=-13%2F6 Reduce

--------------------------------------------------------------
Answer:
So our answer is n=-13%2F6 (which is approximately n=-2.16666666666667 in decimal form)



Linear-equations/115635: 28-2(10x-0.365)=7x+0.035
1 solutions

Answer 84151 by jim_thompson5910(28504) About Me  on 2007-12-09 13:08:36 (Show Source):
You can put this solution on YOUR website!
28-2%2810x-0.365%29=7x%2B0.035 Start with the given equation



28-20x%2B0.73=7x%2B0.035 Distribute


1000%2828-20x%2B0.73%29=1000%287x%2B0.035%29 Multiply both sides by 1000 to move the decimal on each number 3 times. This will make every number a whole number.

28000-20000x%2B730=7000x%2B35 Distribute and multiply



-20000x%2B28730=7000x%2B35 Combine like terms on the left side


-20000x=7000x%2B35-28730Subtract 28730 from both sides


-20000x-7000x=35-28730 Subtract 7000x from both sides


-27000x=35-28730 Combine like terms on the left side


-27000x=-28695 Combine like terms on the right side


x=%28-28695%29%2F%28-27000%29 Divide both sides by -27000 to isolate x



x=1913%2F1800 Reduce

--------------------------------------------------------------
Answer:
So our answer is x=1913%2F1800 (which is approximately x=1.06277777777778 in decimal form)


Polynomials-and-rational-expressions/115569: I cant figure out how to solve ...
(x+4)/3x + (x+8)/5x = 2
1 solutions

Answer 84150 by jim_thompson5910(28504) About Me  on 2007-12-09 13:04:16 (Show Source):
You can put this solution on YOUR website!
%28x%2B4%29%2F%283x%29+%2B+%28x%2B8%29%2F%285x%29+=+2 Start with the given expression



Now multiply both sides by the LCD 15x to eliminate every fraction

%2815x%29%28%28x%2B4%29%2F%283x%29+%2B+%28x%2B8%29%2F%285x%29+%29=%2815x%29%28+2%29


5%28x%2B4%29%2B+3%28x%2B8%29=30x Distribute. Since the fractions are gone, we have to keep in mind that x%3C%3E0




5x%2B20%2B3x%2B24=30x Distribute again


8x%2B44=30x Combine like terms on the left side


8x=30x-44Subtract 44 from both sides


8x-30x=-44 Subtract 30x from both sides


-22x=-44 Combine like terms on the left side


x=%28-44%29%2F%28-22%29 Divide both sides by -22 to isolate x



x=2 Divide

--------------------------------------------------------------
Answer:
So our answer is x=2


Graphs/115626: Please help.
Graph the following inequality
x-y≤2
Thanks
JMS
1 solutions

Answer 84149 by jim_thompson5910(28504) About Me  on 2007-12-09 13:00:42 (Show Source):
You can put this solution on YOUR website!
In order to graph x-y%3C=2, we need to graph the equation x-y=2 (just replace the inequality sign with an equal sign).
So lets graph the line x-y=2 (note: if you need help with graphing, check out this solver)
+graph%28+500%2C+500%2C+-20%2C+20%2C+-20%2C+20%2C+x-2%29+ graph of x-y=2
Now lets pick a test point, say (0,0). Any point will work, (just make sure the point doesn't lie on the line) but this point is the easiest to work with. Now evaluate the inequality x-y%3C=2 with the test point

Substitute (0,0) into the inequality
%280%29-%280%29%3C=2 Plug in x=0 and y=0
0%3C=2 Simplify



(note: for some reason, some of the following images do not display correctly in Internet Explorer. So I recommend the use of
Firefox to see these images.)


Since this inequality is true, we simply shade the entire region that contains (0,0)
Graph of x-y%3C=2 with the boundary (which is the line x-y=2 in red) and the shaded region (in green)


Linear-equations/115633: how do I calculate the slope of the line that pases through the following points:
(-5,-9) and (7,-9)
1 solutions

Answer 84147 by jim_thompson5910(28504) About Me  on 2007-12-09 12:59:30 (Show Source):
You can put this solution on YOUR website!
Solved by pluggable solver: Finding the slope


Slope of the line through the points (-5, -9) and (7, -9)



m+=+%28y%5B2%5D+-+%28y%5B1%5D%29%29%2F%28x%5B2%5D+-+%28x%5B1%5D%29%29


m+=+%28-9+-+%28-9%29%29%2F%287+-+%28-5%29%29


m+=+%28-9+%2B+9%29%2F%287+%2B+5%29


m+=+%280%29%2F%2812%29


m+=+0



Answer: Slope is m+=+0



Linear-equations/115632: Are these two lines perpendicular?
Line 1: y=x+3
Line 2: x-y=13
1 solutions

Answer 84146 by jim_thompson5910(28504) About Me  on 2007-12-09 12:58:42 (Show Source):
You can put this solution on YOUR website!
Let's solve for y in the second equation



x-y=13 Start with the given equation



-y=13-xSubtract x from both sides


y=x-13 Multiply both sides by -1 to isolate y. This will change the sign of all of the terms on the right


Now since the slope of the first line is m=1 and the slope of the second line is also m=1, these two lines are parallel. So they cannot be perpendicular.


Functions/115630: Please help.
Given f(x)=4x+2
find f(a+2)
I came up with the answer of 4a+10. Is this correct?
Thanks
JMS
1 solutions

Answer 84143 by jim_thompson5910(28504) About Me  on 2007-12-09 12:53:37 (Show Source):
You can put this solution on YOUR website!
You are correct. After substitution, you should get f%28a%2B2%29=4a%2B8%2B2 which then becomes f%28a%2B2%29=4a%2B10


Linear-equations/115622: What is the slope and y intercept of the following
y = -x
1 solutions

Answer 84142 by jim_thompson5910(28504) About Me  on 2007-12-09 12:41:37 (Show Source):
You can put this solution on YOUR website!
Let's use the general equation y=mx%2Bb where m is the slope and b is the y-intercept

From y=-x, we can see that m=-1 and b=0 (Remember y=-x really looks like y=-1x%2B0)

So the slope is m=-1 and the y-intercept is b=0


Linear-systems/115597: 2x/3 - 2< or equal to 8 - x
1 solutions

Answer 84141 by jim_thompson5910(28504) About Me  on 2007-12-09 12:18:24 (Show Source):
You can put this solution on YOUR website!

2x%2F3-2%3C=8-1x Start with the given inequality



%283%29%282x%2F3-2%29%3C=%283%29%288-1x%29 Multiply both sides by the LCM of 3. This will eliminate the fractions (note: if you need help with finding the LCM, check out this solver)



2x-6%3C=24-3x Distribute and multiply the LCM to each side



2x%3C=24-3x%2B6Add 6 to both sides


2x%2B3x%3C=24%2B6 Add 3x to both sides


5x%3C=24%2B6 Combine like terms on the left side


5x%3C=30 Combine like terms on the right side


x%3C=%2830%29%2F%285%29 Divide both sides by 5 to isolate x



x%3C=6 Divide

--------------------------------------------------------------
Answer:
So our answer is x%3C=6




Equations/115590: 3/5x - (2-x) = -10
1 solutions

Answer 84140 by jim_thompson5910(28504) About Me  on 2007-12-09 12:16:44 (Show Source):
You can put this solution on YOUR website!

3%2F5x-1%282-1x%29=-10 Start with the given equation



%285%29%283%2F5x-1%282-1x%29%29=%285%29%28-10%29 Multiply both sides by the LCM of 5. This will eliminate the fractions (note: if you need help with finding the LCM, check out this solver)



3x-5%282-1x%29=-50 Distribute and multiply the LCM to each side



3x-10%2B5x=-50 Distribute


8x-10=-50 Combine like terms on the left side


8x=-50%2B10Add 10 to both sides


8x=-40 Combine like terms on the right side


x=%28-40%29%2F%288%29 Divide both sides by 8 to isolate x



x=-5 Divide

--------------------------------------------------------------
Answer:
So our answer is x=-5



Inequalities/115595: 2 - 3x< or equal to 8
1 solutions

Answer 84139 by jim_thompson5910(28504) About Me  on 2007-12-09 12:14:22 (Show Source):
You can put this solution on YOUR website!

2-3x%3C=8 Start with the given inequality



-3x%3C=8-2Subtract 2 from both sides


-3x%3C=6 Combine like terms on the right side


x%3E=%286%29%2F%28-3%29 Divide both sides by -3 to isolate x (note: Remember, dividing both sides by a negative number flips the inequality sign)



x%3E=-2 Divide

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Answer:
So our answer is x%3E=-2




Polynomials-and-rational-expressions/115563: Factor using AC Method. 9x^2-15x-6
1 solutions

Answer 84115 by jim_thompson5910(28504) About Me  on 2007-12-08 23:57:03 (Show Source):
You can put this solution on YOUR website!

Looking at 9x%5E2-15x-6 we can see that the first term is 9x%5E2 and the last term is -6 where the coefficients are 9 and -6 respectively.

Now multiply the first coefficient 9 and the last coefficient -6 to get -54. Now what two numbers multiply to -54 and add to the middle coefficient -15? Let's list all of the factors of -54:



Factors of -54:
1,2,3,6,9,18,27,54

-1,-2,-3,-6,-9,-18,-27,-54 ...List the negative factors as well. This will allow us to find all possible combinations

These factors pair up and multiply to -54
(1)*(-54)
(2)*(-27)
(3)*(-18)
(6)*(-9)
(-1)*(54)
(-2)*(27)
(-3)*(18)
(-6)*(9)

note: remember, the product of a negative and a positive number is a negative number


Now which of these pairs add to -15? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to -15

First NumberSecond NumberSum
1-541+(-54)=-53
2-272+(-27)=-25
3-183+(-18)=-15
6-96+(-9)=-3
-154-1+54=53
-227-2+27=25
-318-3+18=15
-69-6+9=3



From this list we can see that 3 and -18 add up to -15 and multiply to -54


Now looking at the expression 9x%5E2-15x-6, replace -15x with 3x%2B-18x (notice 3x%2B-18x adds up to -15x. So it is equivalent to -15x)

9x%5E2%2Bhighlight%283x%2B-18x%29%2B-6


Now let's factor 9x%5E2%2B3x-18x-6 by grouping:


%289x%5E2%2B3x%29%2B%28-18x-6%29 Group like terms


3x%283x%2B1%29-6%283x%2B1%29 Factor out the GCF of 3x out of the first group. Factor out the GCF of -6 out of the second group


%283x-6%29%283x%2B1%29 Since we have a common term of 3x%2B1, we can combine like terms

So 9x%5E2%2B3x-18x-6 factors to %283x-6%29%283x%2B1%29


So this also means that 9x%5E2-15x-6 factors to %283x-6%29%283x%2B1%29 (since 9x%5E2-15x-6 is equivalent to 9x%5E2%2B3x-18x-6)

-------------------------------
Answer:

So 9x%5E2-15x-6 factors to %283x-6%29%283x%2B1%29


Miscellaneous_Word_Problems/115562: This question is from textbook
Solve each of quadriatic equations. Round to two decimal places if possible. It is not clear how to do this step by step. could someone help please.

x^2=25

1 solutions

Answer 84113 by jim_thompson5910(28504) About Me  on 2007-12-08 23:23:39 (Show Source):
You can put this solution on YOUR website!
x%5E2=25 Start with the given equation


x%5E2-25=0 Move all of the terms to the left side


%28x%2B5%29%28x-5%29=0 Factor the left side (note: if you need help with factoring, check out this solver)



Now set each factor equal to zero:
x%2B5=0 or x-5=0

x=-5 or x=5 Now solve for x in each case


So our answer is
x=-5 or x=5


Notice if we graph y=x%5E2-25 we can see that the roots are x=-5 and x=5 . So this visually verifies our answer.


+graph%28500%2C500%2C-10%2C10%2C-10%2C10%2C0%2C+x%5E2-25%29+


Functions/115559: let f(x)=sqrt x+1 and g(x)=1/x+1 and evaluate
(f*g) (x)
1 solutions

Answer 84112 by jim_thompson5910(28504) About Me  on 2007-12-08 23:18:58 (Show Source):
You can put this solution on YOUR website!
Do you want to do a function composition? If you do, then...

f%28g%28x%29%29 Start with the given composition

f%281%2F%28x%2B1%29%29 Plug in g%28x%29=1%2F%28x%2B1%29

f%281%2F%28x%2B1%29%29=sqrt%281%2F%28x%2B1%29%2B1%29 This means you replace each x of f(x) with 1%2F%28x%2B1%29



Miscellaneous_Word_Problems/115557: The area of a square is 625 mm^2. Find its side length?
1 solutions

Answer 84111 by jim_thompson5910(28504) About Me  on 2007-12-08 23:08:48 (Show Source):
You can put this solution on YOUR website!
Remember, the area of a square is A=s%5E2 where A is the area and s is the side length of the square. So in this case A=625

625=s%5E2 Plug in A=625


sqrt%28625%29=sqrt%28s%5E2%29 Take the square root of both sides


s=25 Simplify

So the length of the side is 25 mm

Does this make sense?


Miscellaneous_Word_Problems/115556: The area of square is 625 mm^2. Find its side length?
1 solutions

Answer 84110 by jim_thompson5910(28504) About Me  on 2007-12-08 23:05:57 (Show Source):
You can put this solution on YOUR website!
Remember, the area of a square is A=s%5E2 where A is the area and s is the side length of the square. So in this case A=625

625=s%5E2 Plug in A=625


sqrt%28625%29=sqrt%28s%5E2%29 Take the square root of both sides


s=25 Simplify

So the length of the side is 25 mm


real-numbers/115555: I really need help with this problem. The problem says to find two consecutive intergers whose product is 90, it must be solved algebraically. Thank You.
1 solutions

Answer 84109 by jim_thompson5910(28504) About Me  on 2007-12-08 23:00:48 (Show Source):
You can put this solution on YOUR website!
Remember, consecutive integers follow the pattern x, x%2B1, etc.

So if their product is 90, then

x%28x%2B1%29=90


x%5E2%2Bx=90 Distribute


x%5E2%2Bx-90=0 Move all of the terms to the left side


%28x%2B10%29%28x-9%29=0 Factor the left side (note: if you need help with factoring, check out this solver)



Now set each factor equal to zero:
x%2B10=0 or x-9=0

x=-10 or x=9 Now solve for x in each case


So our answer is
x=-10 or x=9




So our two numbers are either 9,10 or -10,-9