Question

I would like to know step by step how to solve this problem.

Answer 1

`\sf{}\\Solution:\\f(x)=x-7,\\g(x)=x^2\\Now,\\gof(x)=g\{f(x)\}=g(x-7)^2\\\therefore\ gof(x)=(x-7)^2`

`\sf\\\therefore\ g(f(4))=gof(4)=(4-7)^2=(-3)^2=9`