Answer:
[tex]f^{-1}[/tex] (x) = [tex]\frac{x-9}{7}[/tex]
Step-by-step explanation:
let y = f(x) and rearrange making x the subject
y = 7x + 9 ( subtract 9 from both sides )
y - 9 = 7x ( divide both sides by 7 )
[tex]\frac{y-9}{7}[/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-9}{7}[/tex]
