a) \(\left\{ \begin{array}{l}{x^2} \ge 0,25\\{x^2} - x \le 0\end{array} \right.\) \( \Leftrightarrow \left\{ \begin{array}{l}{x^2} - 0,25 \ge 0\\{x^2} - x \le 0\end{array} \right.\) \( \Leftrightarrow 0,5 \le x \le 1.\)
b) \(\left\{ \begin{array}{l}(x - 1)(2x + 3) > 0\\(x - 4)(x + \dfrac{1}{4}) \le 0\end{array} \right.\) \( \Leftrightarrow \left\{ \begin{array}{l}x \in ( - \infty ; - \dfrac{3}{2}) \cup (1; + \infty )\\x \in {\rm{[ - }}\dfrac{1}{4}{\rm{;4]}}\end{array} \right.\) \( \Leftrightarrow x \in (1;4].\)
