$\begin{array}{l} \left\{ \begin{array}{l} 2{x^2} - 3x - 2 < 0\\ 1 - 4{x^2} \ge 0 \end{array} \right. \Leftrightarrow \left\{ \begin{array}{l} \left( {x - 2} \right)\left( {2x + 1} \right) < 0\\ \left( {1 - 2x} \right)\left( {1 + 2x} \right) \ge 0 \end{array} \right. \Leftrightarrow \left\{ \begin{array}{l} \dfrac{{ - 1}}{2} < x < 2\\ - \dfrac{1}{2} \le x \le \dfrac{1}{2} \end{array} \right. \Rightarrow \dfrac{{ - 1}}{2} < x \le \dfrac{1}{2}\\ \to S\left( { - \dfrac{1}{2};\dfrac{1}{2}} \right] \end{array}$
