The Function F Is One-To-One $$f ( x ) = \frac { 9 } { x - 4 }$$

Multiple Choice

The function f is one-to-one. Find its inverse.
- $$f ( x ) = \frac { 9 } { x - 4 }$$

A) $\mathrm { f } ^ { - 1 } ( \mathrm { x } ) = \frac { 4 \mathrm { x } + 9 } { \mathrm { x } }$
B) $f ^ { - 1 } ( x ) = \frac { x } { - 4 + 9 x }$
C) $f ^ { - 1 } ( x ) = \frac { - 4 + 9 x } { x }$
D) $f ^ { - 1 } ( x ) = \frac { - 4 + 9 x ^ { 2 } } { x }$