What is the inverse of the function f(x) = 2x – 10?

Replace f(x) with y and proceed to make x the subject:
y=2x-10
y+10=2x
y+10/2=x
Now swap y with x and replace the isolated x with f(x), so

Same length is comparing because it’s saying its the same and not different

What mathematical statement is missing ? ? the answer is b