Question

If f(x) = 9x – 8, which of the following is the inverse of f(x)?

Answer 1

Answer: $f^{-1}$ (x) = $\frac{x+8}{9}$

Step-by-step explanation:

f(x) = 9x - 8 , to find the inverse of f(x) , replace f(x) with y , then the equation becomes

y = 9x - 8 , then make x , the subject of the formula ,

9x = y + 8

x = $\frac{y+8}{9}$

Finally , replace x , with $f^{-1}$ (x) and y with x  , so we have

$f^{-1}$ (x) = $\frac{x+8}{9}$