SOLUTION: How do you solve: using substitution 5x-2y=-7 8=y-4x

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Question 301316: How do you solve: using substitution
5x-2y=-7
8=y-4x
Found 2 solutions by richwmiller, Stitch:
Answer by richwmiller(17219) (Show Source):
You can put this solution on YOUR website!
first you have to rearrange the second.
4x+8=y
now plug 4x+8 for y in the first
5x-2*(4x+8)=-7
5x-8x-16=-7
-3x=9
x=-3
now plug that into the second and solve for y
8=y-4*(-3)
8=y+12
-4=y
(x,y)=(-3,-4)

Answer by Stitch(470) (Show Source):
You can put this solution on YOUR website!
Set-Up:
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Equation 1:
Equation 2:
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Solution:
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You need to solve one of the equations for one variable. in this case I thin that solving equation 2 for Y is the easiest.
Equation 2: Add 4X to both sides

Now you can plug (8 + 4X) into equation 1 for Y
Equation 1:
Simplify
Simplify
Add 16 to both sides
Divide both sides by -3

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Now plug -3 into equation 2 for X