Question

Sejam f e g funcoes reais, dadas por f(x)=2x-3e f(g(x))=-4x+1. Nestas condicoes, calcule g(-1)

Answer 1

 Olá Carolina!

$f(x)=2x-3\\f(g(x))=2\cdot\,g(x)-3\\-4x+1=2\cdot\,g(x)-3\\2\cdot\,g(x)=-4x+1+3\\2\cdot\,g(x)=-4x+4\;\;\div(2\\g(x)=-2x+2\\g(-1)=-2\cdot(-1)+2\\g(-1)=2+2\\\boxed{g(-1)=4}$