Solve the system using substitution

y=8-x

7=2-y

If y=8-x then you can plug that into the equation like 7=2 - (8-x). When you distribute the equation becomes 7=2-8+x. Once you combine like terms the equation becomes 7=-6+x. Then you subtract 6 from both sides, which gives you 13=x.

To find y just put 13 where x was in the first equation. Y=8-13.

Y=-5

X=13