Answer:
1st option
Step-by-step explanation:
let y = f(x) and rearrange making x the subject , that is
y = [tex]\frac{1}{9}[/tex] x - 2 ( add 2 to both sides )
y + 2 = [tex]\frac{1}{9}[/tex] x ( multiply both sides by 9 to clear the fraction )
9(y + 2) = x
9y + 18 = x
change y back into terms of x with x = [tex]f^{-1}[/tex] (x) , then
[tex]f^{-1}[/tex] (x) = 9x + 18
