Đáp án: $x\in \left \{ -3;\dfrac{1}{3} \right \}$
Giải thích các bước giải:
$(3x-1)(2x+6)<0\\\Leftrightarrow \left[ \begin{array}{l}\left\{\begin{matrix}
3x-1<0\\
2x+6>0
\end{matrix}\right.\\\left\{\begin{matrix}
3x-1>0\\
2x+6<0
\end{matrix}\right.\end{array} \right.\\\Leftrightarrow \left[ \begin{array}{l}\left\{\begin{matrix}
x<\dfrac{1}{3}\\
x>-3
\end{matrix}\right.\\\left\{\begin{matrix}
x>\dfrac{1}{3}\\
x<-3
\end{matrix}\right.\end{array} \right.\\\Leftrightarrow \left[ \begin{array}{l}x\in \left \{ -3;\dfrac{1}{3} \right \}\\x\in \varnothing \end{array} \right.$
