[tex]\bf \begin{cases} ~\hfill f(x) = &-3x+4\\ ~\hfill g(x) = &x^2\\ (g \circ f)(0)=&g(~~f(0)~~) \end{cases} \\\\[-0.35em] ~\dotfill\\\\ f(0) = -3(0)+4\implies \boxed{f(0) = 4} \\\\\\ g(~~f(0)~~)\implies g\left( \boxed{4} \right) = (4)^2\implies \stackrel{(g \circ f)(0)}{g(4)} = 16[/tex]
