Solve the Problem $f ( x ) = \frac { x - 7 } { x + 5 }$

Multiple Choice

Solve the problem.
-Given $f ( x ) = \frac { x - 7 } { x + 5 }$ , find all values for $x$ for which $f ( x ) < 0$ .

A) $( - \infty , - 5 ) \cup ( 7 , \infty )$
B) $( 7 , \infty )$
C) $( - \infty , - 5 )$
D) $( - 5,7 )$