$ \left\{ \begin{array}{l}3x-1≥0\\3x≤(m-1)(2m-3)\end{array} \right.$
$\Leftrightarrow \left\{ \begin{array}{l}3x-1≥0\\3x≤2m^2-5m+3\end{array} \right.$
$ \Leftrightarrow \left\{ \begin{array}{l}x≥\dfrac{1}{3}\\x≤\dfrac{2m^2-5m+3}{3}\end{array} \right.$
$\Leftrightarrow \dfrac{1}{3}≤\dfrac{2m^2-5m+3}{3}$
$\Leftrightarrow 2m^2-5m+2 ≥0$
$\Leftrightarrow x≤\dfrac{1}{2}$ hay$2≤x$ thoả ycbt
