Resposta :
[tex]\Large\boxed{\begin{array}{l}\sf g(x)=x+2\\\sf f(x)=2x\\\sf g([f(x)])=2\cdot f(x)\\\sf g([f(x)])=2\cdot(x+2)\\\sf g([f(x)])=2x+4\end{array}}[/tex]
[tex]\Large\boxed{\begin{array}{l}\sf g(x)=x+2\\\sf f(x)=2x\\\sf g([f(x)])=2\cdot f(x)\\\sf g([f(x)])=2\cdot(x+2)\\\sf g([f(x)])=2x+4\end{array}}[/tex]