詳解：上下有共同因式

\(\lim \limits_{x \to 3} \frac{{{x^2} - x - 6}}{{x - 3}} = \lim \limits_{x \to 3} \frac{{\left( {x + 2} \right)\left( {x - 3} \right)}}{{x - 3}} = \lim \limits_{x \to 3} \left( {x + 2} \right) = 3 + 2 = 5\)