\[\left\{ \begin{matrix} x² - 5x - 14 \leq 0\ \ (1) \\ 3x + 6 \leq 0\ \ \ \ \ \ \ \ \ \ \ \ \ \ (2) \\ \end{matrix} \right.\ \]
\[(1)\ x_{1} + x_{2} = 5,\ \ \ x_{1} + x_{2} = - 14\]
\[x_{1} = 7,\ \ x_{2} = - 2\]
\[(2)\ x \leq - 2\]
\[Ответ:\ \left\{ - 2 \right\}.\]