Given f-1(x)=-3/4x+2 which equation represents f(x)

1. Here the question is either

a: f(x-1)=, what is f(x)?
or
b) f(1-x)=, what is f(x)?

Case a: f(x-1)=, what is f(x)?

substitute x with x+1 in both sides. The reason is to get rid of 1 in the f() expression:

f((x+1)-1)=

f(x+1-1)=

f(x)=

b) in case b substitute x with (1-x) in both sides so that we get:
f(1-x)=f(1-(1-x))=f(1-1+x)=f(x)