Question

Se f(x)=3x-4 e f(g(x))=x+4, então g(1) vale:

Answer 1

Oi Kaly.

$f(g(x))=x+4\\ f(x)=3x-4\\ \\ f(g(x))=3g(x)-4\\ \\ 3g(x)-4=x+4\\ 3g(x)=x+4+4\\ 3g(x)=x+8\\ g(x)=\frac { x+8 }{ 3 } \\ \\ g(1)=\frac { 1+8 }{ 3 } =\frac { 9 }{ 3 } \Rightarrow 3$