ANSWER
The correct answer is A
[tex]f^{-1}(x)=\frac{x+b}{a}[/tex]
EXPLANATION
Given [tex]f(x)=ax-b[/tex].
We can find the inverse by taking the steps.
1. Let [tex]y=ax-b[/tex]
2. Interchange x and y
[tex]x=ay-b[/tex]
3. Make y the subject
[tex]x+b=ay[/tex]
[tex]\frac{x+b}{a}=y[/tex]
The new function we got now is the inverse of f(x)
[tex]f^{-1}(x)=\frac{x+b}{a}[/tex]
