Answer:
[tex]\tt C) \:\tt f^{-1}(x)=\cfrac{x-6}{3}[/tex]
Step-by-step explanation:
We're given,
[tex]\tt f(x) = 3x + 6[/tex]
~
[tex]\tt y=3x+6[/tex]
[tex]\tt x=3y+6[/tex]
[tex]\tt x-6=3y[/tex]
[tex]\tt y=\cfrac{x-6}{3}[/tex]
[tex]\tt f^{-1}(x)=\cfrac{x-6}{3}[/tex]
~
