Question

FOR F(X)=X^2+7 AND G(X)=X^2-7 FIND
(FoG)(X)
(GoF)(X)
(FoG)(4)

Answer 1

fog=f[g(x)] which means in f(x) instead of x put all g(x)
gof=g[f(x)] which means in g(x) instead of x put all f(x)
and after u've found fog instead of x put 4