Yes you're right.
The way to find out if functions are inverses of each other is to check
and see if their composite functions are equal to x. Also make sure the
functions are one to one functions.
(fog)(x)=f(g(x))=f(3/2x-9)
f(3/2x-9)=2/3(3/2x-9)+6
=(2/3)(3/2)x+(2/3)(-9/1)+6
=x-18/3+6
=x-6+6
I hope this helped! #Sobangcha
