Đáp án:
$\begin{array}{l}
\mathop {\lim }\limits_{x \to - 6} \dfrac{{{x^2} + 7x + 6}}{{x + 6}}\\
= \mathop {\lim }\limits_{x \to - 6} \dfrac{{\left( {x + 6} \right)\left( {x + 1} \right)}}{{x + 6}}\\
= \mathop {\lim }\limits_{x \to - 6} \left( {x + 1} \right)\\
= - 6 + 1\\
= - 5\\
\Leftrightarrow \mathop {\lim }\limits_{x \to - 6} f\left( x \right) = f\left( { - 6} \right)\\
\Leftrightarrow - 5 = 3m + 2\\
\Leftrightarrow 3m = - 7\\
\Leftrightarrow m = \dfrac{{ - 7}}{3}
\end{array}$
