Question

Se f(x)=-x+4 e g(x)=x²+3x. calcule f(g(x))

Answer 1

$\large\boxed{\begin{array}{l}\sf f(x)=-x+4~~g(x)=x^2+3x\\\sf f(g(x))= -g(x)+4\\\sf f(g(x))=-(x^2+3x)+4\\\sf f(g(x))=-x^2-3x+4\end{array}}$