Solve using substitution. I know that the answer is (1,1), but I have to show my work and I forgot how to do it.

If y = -x + 2, then substituting this into the first equation lets you solve for x :
x + 4y = 5
x + 4 (-x + 2) = 5
x - 4x + 8 = 5
-3x = -3
x = 1
Now solve for y :
y = -x + 2 = -1 + 2 = 1
So the solution is indeed (x, y ) = (1, 1).