Evaluate the Function for the Given Value of X $$r ( x ) = 3 x , p ( x ) = x ^ { 2 } + 6 x , ( p - r ) ( x )$$

Multiple Choice

Evaluate the function for the given value of x.
- $$r ( x ) = 3 x , p ( x ) = x ^ { 2 } + 6 x , ( p - r ) ( x )$$

A) $( p - r ) ( x ) = x ^ { 2 } - 3 x$
B) $( p - r ) ( x ) = x ^ { 2 } + 9 x$
C) $( p - r ) ( x ) = x ^ { 2 } + 18 x$
D) $( p - r ) ( x ) = x ^ { 2 } + 3 x$