a)\(\dfrac{x-2}{x+3}>0\Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}x-2>0\\x+3>0\end{matrix}\right.\\\left\{{}\begin{matrix}x-2< 0\\x+3< 0\end{matrix}\right.\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}x>2\\x>-3\end{matrix}\right.\\\left\{{}\begin{matrix}x< 2\\x< -3\end{matrix}\right.\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x>2\\x< -3\end{matrix}\right.\)
b) Vì 2>-5 =>x+2>x-5
\(\dfrac{x+2}{x-5}< 0\Leftrightarrow\left\{{}\begin{matrix}x+2>0\\x-5< 0\end{matrix}\right.\)vì x+2>x-5 \(\Leftrightarrow\left\{{}\begin{matrix}x>-2\\x< 5\end{matrix}\right.\Leftrightarrow-2< x< 5}\)
câu b bạn có thể làm rõ hơn