SOLUTION: SOLVE EACH SYSTEM BY SUBSTITUTION [x=y-8 [-x-y=0

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Question 249056: SOLVE EACH SYSTEM BY SUBSTITUTION
[x=y-8
[-x-y=0
Answer by tutorcecilia(2152) About Me  (Show Source):
You can put this solution on YOUR website!
x=y-8 [substitue this equation into the second equation wherever there is an "x"]
-x-y=0 [second equation]
-(y-8)-y=0 [plug-in first equation for "x"]
-y+8-y=0 [solve for the y-value]
-2y+8=0
-2y=-8
-2y/-2=-8/-2
y=4
check by plugging "x" back into either equation.