Given the Polynomial Functions, Find the Product Function and the Specified

Multiple Choice

Given the polynomial functions, find the product function and the specified value.
-Let $f ( x ) = x + 3$ and $g ( x ) = x ^ { 2 } - 9 x - 7$ . Find $( f g ) ( x )$ and $( f g ) ( - 4 )$ .

A) $( f g ) ( x ) = 3 x ^ { 3 } + 27 x ^ { 2 } - 21 x ; ( f g ) ( - 4 ) = - 540$
B) $( f g ) ( x ) = x ^ { 3 } + 12 x ^ { 2 } + 34 x + 21 ; ( f g ) ( - 4 ) = 285$
C) $( f g ) ( x ) = x ^ { 3 } - 6 x ^ { 2 } - 34 x - 21 ; ( f g ) ( - 4 ) = - 45$
D) $( \mathrm { fg } ) ( \mathrm { x } ) = \mathrm { x } ^ { 3 } - 9 \mathrm { x } ^ { 2 } - 7 \mathrm { x } ; ( \mathrm { fg } ) ( - 4 ) = - 180$