Đáp án:
$1/$
Để $ [2;3] ⊂ (-∞;m)$ thì $m \ge 3$
$2/$
Để $(-3;m) ⊂ (-∞; 4m+1)$ thì \(\left[ \begin{array}{l}m \ge -3\\m \le 4m+1\end{array} \right.\)
$<=>$\(\left[ \begin{array}{l}m ge -3\\m \ge -\frac{1}{3} \end{array} \right.\)
$=>m \ge -\frac{1}{3}$