Question 651531
x+y=8 y=-x+8
x-y=12
x-(-x+8)=12
2x-8=12
2x=12+8
x=20/2
x=10
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10-y=12
-y=12-10
-y=2
y=-2
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10-2=8
I don't know where you got the 30 from.