SOLUTION: How to use substitution? X=-4Y and 3X+2Y=20 Im lost..please help me!

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Question 426260: How to use substitution?
X=-4Y
and
3X+2Y=20
Im lost..please help me!
Answer by rfer(16322) About Me  (Show Source):
You can put this solution on YOUR website!
3(-4y)+2y=20
-12y+2y=20
-10y=20
y=-2
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3x+2*-2=20
3x-4=20
3x=24
x=8
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proof
x=-4y
8=-4*-2