We are asked to find z = g0f or what is the same: z = g (f (x)) That is, we must introduce the function f (x) within the function g (x) So, we have f (x) = 3x-9 g (x) = x ² Therefore we have the following function z = (3x-9) ² Finally (g0f) (5) = (3 (5) -9) ² (g0f) (5) = 36
