Respuesta :

osinachukwunwosu

Answer:

9

Explanation:

let f(x)= x-7 be equation i

let g(x)= x^2 be equation ii

Substitute x-7 as x in equation 2

implies gf(x) = (x-7)^2=(x-7)(x-7)

              substitute x=4 implies

gf(x) = (4-7)(4-7)=(-3)(-3)=9