(3) Solve the inequality $m x-2 \geqslant 3 x-4 m$ for $x$, where the constant $m \in \mathbf{R}$.
(3) When $m>3$, $x \geqslant \frac{2-4 m}{m-3}$; when $m<3$, $x \leqslant \frac{2-4 m}{m-3}$; when $m=3$, $x$ is any real number