\(3x^2-2x-8=0\\ \Leftrightarrow\left(3x^2-6x\right)+\left(4x-8\right)=0\\ \Leftrightarrow3x\left(x-2\right)+4\left(x-2\right)=0\\ \Leftrightarrow\left(3x+4\right)\left(x-2\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{4}{3}\\x=2\end{matrix}\right.\)
\(\Leftrightarrow3x^2-6x+4x-8=0\)
=>(x-2)(3x+4)=0
=>x=2 hoặc x=-4/3
\(\left[{}\begin{matrix}x-2=0\\x+\dfrac{4}{3}=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=2\\x=\dfrac{-4}{3}\end{matrix}\right.\)
\(\left(x-2\right)\left(3x-4\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}\dfrac{-4}{3}\\2\end{matrix}\right.\)
