Question

giải các pt

(3x-2)(4x+5)=0

Answer 1

`(3x-2)(4x+5)=0`

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

Answer 2

\(\left(3x-2\right)\left(4x+5\right)=0\)

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

\(\text{Vậy phương trình có tập nghiệm là }S=\left\{\dfrac{2}{3};\dfrac{-5}{4}\right\}\)