Giải thích các bước giải:
a,
\(\begin{array}{l}
\left\{ \begin{array}{l}
3x - 2 > - 4x + 5\\
3x + m + 2 < 0
\end{array} \right.\\
\Leftrightarrow \left\{ \begin{array}{l}
7x > 7\\
x < - \frac{{m + 2}}{3}
\end{array} \right.\\
\Leftrightarrow \left\{ \begin{array}{l}
x > 1\\
x < - \frac{{m + 2}}{3}
\end{array} \right.\\
\Rightarrow - \frac{{m + 2}}{3} > 1\\
\Leftrightarrow \frac{{m + 2}}{3} > - 1\\
\Leftrightarrow m > - 5\\
b,\\
\left\{ \begin{array}{l}
x - 2 \le 0\\
m + x > 1
\end{array} \right.\\
\Leftrightarrow \left\{ \begin{array}{l}
x \le 2\\
x > 1 - m
\end{array} \right.\\
\Rightarrow 1 - m \le 2\\
\Leftrightarrow m \ge - 1
\end{array}\)
