ĐKXĐ: \(\left\{{}\begin{matrix}2x^2-7x+3\ge0\\-2x^2+9x-4\ge0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}\left[{}\begin{matrix}x\le\frac{1}{2}\\x\ge3\end{matrix}\right.\\\frac{1}{2}\le x\le4\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\frac{1}{2}\\3\le x\le4\end{matrix}\right.\)