\(2x\left(x-3\right)=x^2-3x\)
\(\Rightarrow2x\left(x-3\right)=x\left(x-3\right)\)
\(\Rightarrow2x=x\)
\(\Rightarrow x=0\)
\(2x.\left(x-3\right)=x^2-3x\)
\(\left(x-3\right)=x^2-3x:2x\)
Ta có: \(2x\left(x-3\right)=x^2-3x\)
\(\Leftrightarrow2x\left(x-3\right)-x\left(x-3\right)=0\)
\(\Leftrightarrow x\left(x-3\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=3\end{matrix}\right.\)