Answer:
[tex]f^{-1}[/tex] (x) = [tex]\frac{x+b}{a}[/tex]
Step-by-step explanation:
let y = f(x) and rearrange making x the subject
y = ax - b ( add b to both sides )
y + b = ax ( divide both sides by a )
[tex]\frac{y+b}{a}[/tex] = x
Change y back into terms of x with x = [tex]f^{-1}[/tex] (x) , then
[tex]f^{-1}[/tex] (x) = [tex]\frac{x+b}{a}[/tex]
