Question

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.

Answer 1

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).