Answer: f-1(x) = 9x + 18.
Step-by-step explanation:
let y = f(x) and rearrange making x the subject, that is
y = x - 2 ( add 2 to both sides )
y + 2 = x
Multiply through by 9 to clear the fraction
9y + 18 = x
Change y back into terms of x
(x) = 9x + 18
