\[\left\{ \begin{matrix} 2x \geq 4\ \ \ \\ 9x \leq 18 \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ }\]
\[\left\{ \begin{matrix} x \geq 2 \\ x \leq 2 \\ \end{matrix} \right.\ \]
\[Ответ:\ \left\{ 2 \right\}.\]