## Precalculus (6th Edition) Blitzer

$(-\infty, -5) \cup (-5, +\infty)$
The denominator cannot be zero since division of zero is undefined. The number $-5$ makes the denominator zero. Thus, the domain of the given function is the set of all real numbers except $-5$. In interval notation, the domain is: $(-\infty, -5) \cup (-5, +\infty)$