( 2x + 5 )( x - 3 ) < 0
⇔ \(\left[ \begin{array}{l}2x+5<0\\x-3<0\end{array} \right.\)
⇔ \(\left[ \begin{array}{l}x< \frac{-5}{2} \\x<3\end{array} \right.\)
⇒ x < $\frac{-5}{2}$
( 2 - x )( x + 3 ) < 0
⇔ \(\left[ \begin{array}{l}2-x<0\\x+3<0\end{array} \right.\)
⇔ \(\left[ \begin{array}{l}x>2\\x<-3\end{array} \right.\)
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