\(\left(x+2\right)\left(x-4\right)=0\\ \Rightarrow\left[{}\begin{matrix}x+2=0\\x-4=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=-2\\x=4\end{matrix}\right.\)
\(\left[{}\begin{matrix}x+2=0\\x-4=0\end{matrix}\right.< =>\left[{}\begin{matrix}x=-2\\x=4\end{matrix}\right.\)
( x + 2 ) ( x - 4 ) = 0
TH1: x + 2 = 0 TH2: x - 4 = 0
=> x = -2 => x = 4
Vậy x = -2 hoặc x = 4