Answer
$4$
Work Step by Step
$\lim _{x\rightarrow 3}\dfrac {x^{2}-2x-3}{x-3}=\dfrac {x^{2}-2x-9+6}{x-3}=\dfrac {x^{2}-9-\left( 2x-6\right) }{x-3}=\dfrac {\left( x-3\right) \left( x+3\right) -2\left( x-3\right) }{x-3}=\dfrac {\left( x-3\right) \left( x+1\right) }{x-3}=x+1=3+1=4$
