find the inverse function F -1 (X) for the given function F (X)

Solution for question 5:
f(x) = 4x - 8
To find f^-1(x) write it as an equation:
y = 4x - 8
Then take x to left and y to right;
x = 4y - 8
Then solve for y;
y = (x + 8)/4 = x/4 + 2
Your y is the inverse of f(x) = 4x - 8
f^-1(x) = x/4 + 2