`(2x-4)(x^2+3x-4)=0`
`⇔(2x-4)(x^2-x+4x-4)=0`
`⇔2(x-2)[x(x-1)+4(x-1)]=0`
`⇔2(x-2)(x+4)(x-1)=0`
`⇔(x-2)(x+4)(x-1)=0`
`⇔` \(\left[ \begin{array}{l}x-2=0\\x+4=0\\x-1=0\end{array} \right.\) `⇔` \(\left[ \begin{array}{l}x=2\\x=-4\\x=1\end{array} \right.\)
$\text{Vậy x ∈ {1; 2; -4}}$