Question

Inversa de f(x)=3x+21

Answer 1

Eh soh trocar x e f(x) de lugar:

$f(x)=3x+21\\\\x=3f^{-1}(x)+21\\\\x-21=3f^{-1}(x)\\\\f^{-1}(x)=\dfrac{x-21}{3}$