- 4x - 4y = 28- - - - - -Equation 1
- 2x - 4y = 32- - - - - -Equation 2
- - - - - - - - - -
Multiply equation 1 by - 1
- 4x - 4y = 28
- (- 1)(4x) - (- 1)(4y) = - 1(28)
-(- 4x) - (- 4y) = - 28
4x + 4y = - 28
- - - - - - - - - - -
4x + 4y = - 28
- 2x - 4y = 32
- - - - - - - - - - -
2x = 4
2x / 2 = 4/4
x = 4/2
x = 2
Insert the x value into equation 1
- - - - - - - - - - -
- 4x - 4y = 28
- 4(2) - 4y = 28
- 8 - 4y = 28
- 8 - 4y + 8 = 28 + 8
- 4y = 36
- 4y / - 4 = 36 / - 4
y = 36 / - 4
y = - 9
Insert the y value into equation 1
- - - - - - - - - - - -
Check for equation 1
- 4x - 4y = 28
- 4(2) - 4( - 9) = 28
- 8 - (- 36) = 28
- 8 + 36 = 28
28 = 28
- - - - - - - - - - -
Check for equation 2
- 2x - 4y = 32
- 2(2) - 4(- 9) = 32
- 4 - ( - 36) = 32
- 4 + 36 = 32
32 = 32
- - - - - - - - - -
Both equations balance
The solution set { 2, - 9 }
- - - - - - - -s-
2007-06-12 03:32:10
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answer #1
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answered by SAMUEL D 7
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If we multiply each term of the second equation by -1, we can write the system as
-4x - 4y = 28
2x + 4y = -32
Then, we can eliminate the variable y by adding like terms of this system of equations.
-2x + 0 = -4
-2x = -4
x = 2
If x = 2 and -4x - 4y = 28, then
-4(2) - 4y = 28
-8 - 4y = 28
-4y = 36
y = -9
So, the solution for this system of linear equations is the ordered pair (x, y) = (2, -9).
2007-06-12 03:02:22
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answer #2
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answered by mathjoe 3
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You have
-4x-4y = 28
-2x-4y = 32
substract the second from the first, giving
-2x = -4 , then dividing by -2, yieldx x = 2
Now substitute x=2 into either equation, using the first
-4(x) -4y = 28 or -8-4y = 28, which gives
-4y = 36, dividing by =4 gives y = -9.
substituting these solutions into both equations, proves they are correct.
2007-06-12 03:00:11
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answer #3
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answered by Anonymous
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-4x - 4y=28
-2x-4y=32
(-2x-4y=32)-1= 2x + 4y= -32
-4x-4y=28
2x+4y=-32
-2x=-4
x=2
-4(2)-4y=28
-8-4y=28
-4y=36
y= -9
x=2 y= -9
2007-06-12 02:59:47
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answer #4
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answered by NOT as smart as a 5th grader 4
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4x + 4y = - 28
-2x - 4y = 32----ADD
2x = 4
x = 2
- 8 - 4y = 28
- 36 = 4y
y = - 9
SOLUTION is x = 2 , y = - 9
2007-06-12 03:50:09
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answer #5
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answered by Como 7
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when you're turning out to be questions and function the want to make the guidelines integers, try this. verify the answer in improve. x=2, y=3 create the equations: 2x+3y=2(2)+3(3)=13 2x+3y=13 ----(a million) -x+4y=-2+4(3)=10 -x+4y=10 ---(2) 2x+3y = 13 ---- (a million) -x +4y =10 --- (2)
2016-11-23 13:45:28
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answer #6
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answered by Anonymous
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x=2 y= -9
2007-06-12 03:00:47
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answer #7
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answered by varagani n 1
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(-2,9)
2007-06-12 03:00:13
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answer #8
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answered by Anonymous
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