Answer: x = 0, y = 7
-x+y=7
add x to both sides
y=x+7
plug this in for y in the other equation
6x-(x+7)=-7
simplify
6x-x-7=-7
simplify
5x-7=-7
add 7 to both sides
5x=0
divide both sides by 5
x=0
plug in to one of the equations to find y
-(0)+y=7
y=7
Therefore, x=0 and y=7.
Hope this helps!