f ( x ) = ( 3 x + 12 ( ) x − 2 ) ( x − 1 ) ( x + 5 ) {\displaystyle f(x)={\frac {(3x+12()x-2)}{(x-1)(x+5)}}}
f ( x ) = ( x 2 − 9 ) ( x − 3 ) {\displaystyle f(x)={\frac {(x^{2}-9)}{(x-3)}}}
f ( x ) = ( x − 3 ) ( x 2 − 9 ) {\displaystyle f(x)={\frac {(x-3)}{(x^{2}-9)}}}
f ( x ) = ( x 2 + 4 x ( x 2 − 16 ) {\displaystyle f(x)={\frac {(x^{2}+4x}{(x^{2}-16)}}}