#### Answer

$2$

#### Work Step by Step

$\log \left( x^{2}-9\right) -\log \left( x-3\right) =\log 5$
$\Rightarrow \log \dfrac {\left( x^{2}-9\right) }{\left( x-3\right) }=\log 5\Rightarrow \log \left[ \dfrac {\left( x-3\right) \left( x+3\right) }{x-3}\right] =\log 5$
$\Rightarrow \log \left( x+3\right) =\log 5\Rightarrow x+3=5\Rightarrow x=2$