[tex]\bf \begin{cases} f(x)=2x+6\\ g(x)=x^2+6\\ (g\circ f)(x)\implies g(~~f(x)~~) \end{cases} \\\\[-0.35em] ~\dotfill\\\\ f(1)=2(1)+6\implies f(1)=\boxed{8} \\\\[-0.35em] ~\dotfill\\\\ g(~~f(1)~~)\implies g\left(\boxed{8} \right)=(8)^2+6\implies g(8)=64+6\implies \stackrel{g(~~f(1)~~)}{g(8)}=70[/tex]
