If f(x) = x + 7 a

Formula:-

(i)Let f : AB and g : BC be two functions.

Then, the composition of f and g, denoted by g o f, is defined as the function g o f : AC

given by g o f (x) = g (f (x))

Given:-

(i)f(x) = x + 7

(ii)g(x) = x – 7, x ϵ R

Fog(7)=f(g(7))

Fog(7)=f(7-7)

Fog(7)=f(0)

Fog(7)=0+7

Fog(7)=7