$\begin{array}{l}
f\left( x \right) = \sqrt {3 + x} - \sqrt {2 - x} \\
TXD:D = \left[ { - 3;2} \right]\\
f'\left( x \right) = \frac{1}{{2\sqrt {3 + x} }} + \frac{1}{{2\sqrt {2 - x} }} > 0,\forall x \in D\\
\Rightarrow hs\,dong\,bien\,tren\,D.\\
\Rightarrow f\left( { - 3} \right) \le f\left( x \right) \le f\left( 2 \right) \Leftrightarrow - \sqrt 5 \le f\left( x \right) \le \sqrt 5 \\
Vay\,de\,phuong\,trinh\,da\,cho\,co\,nghiem\,thi\, - \sqrt 5 \le m \le \sqrt 5
\end{array}$
