Respuesta :

Answer:

[tex]\boxed{\sf \ \ f^{-1}(x)=\dfrac{x-6}{3} \ \ }[/tex]

Step-by-step explanation:

hello,

we can write

[tex]fof^{-1}(x)=x \ and \ fof^{-1}(x)=f(f^{-1}(x))=3f^{-1}(x)+6 \ so\\3f^{-1}(x)+6=x \ \ subtract \ 6\\<=>3f^{-1}(x)=x-6 \ \ divide \ \ by \ \ 3\\<=> f^{-1}(x)=\dfrac{x-6}{3}[/tex]

hope this helps