Question 249056
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.