\(\left(3x-2\right)\left(4x+5\right)=0\Leftrightarrow\left[{}\begin{matrix}3x-2=0\\4x+5=0\end{matrix}\right.\) \(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{2}{3}\\x=-\dfrac{5}{4}\end{matrix}\right.\)
vậy \(x=\dfrac{2}{3}\) hoặc \(x=-\dfrac{5}{4}\)