Using subsitution method y=x and y=-x + 2.
y = x
y = -x + 2
Well both are solved for y already so you can substitute the 2nd equation into the first or vice versa.
-x + 2 = x
2x = 2 Subtract x from both sides(I rewrote it in this orientation).
x = 1
If x = 1
y = 1