\[\left\{ \begin{matrix} x² - 7x - 18 \geq 0\ \ (1) \\ - 3,1 \leq x \leq 15,4\ \ \ \ \ \ \ \ \ \\ \end{matrix} \right.\ \]
\[(1)\ x_{1} + x_{2} = 7,\ \ \ x_{1} \cdot x_{2} = - 18\]
\[x_{1} = 9,\ \ x_{2} = - 2\]
\[\lbrack - 3,1;\ - 2\rbrack \cup \lbrack 9;15,4\rbrack\]
\[Ответ:\ - 3;\ - 2;9;10;11;12;\]
\[13;14;15.\]