Finding the inverse of an equation is fairly simple, and from there, it’s a matter of plugging in the desired input.
First, the inverse. Substitute x for y in the original equation and solve for y again to get it in the proper form.
y = (2x + 2)/4
x = (2y + 2)/4
4x = 2y + 2
4x - 2 = 2y
2x - 1 = y
Now, you can just plug in 5 to get the answer.
2(5) - 1 = 9
