Tìm x thuộc Z biết 2x.(x-3)=0

2x.(x-3)=0

⇒\(\left[ \begin{array}{l}2x=0\\x-3=0\end{array} \right.\)

⇒\(\left[ \begin{array}{l}x=0:2\\x=0+3\end{array} \right.\) 

⇒\(\left[ \begin{array}{l}x=0\\x=3\end{array} \right.\)

Vậy x ∈{0;3}