\(\left|x^2-3x\right|=\left|x-3\right|\)
<=>\(\left[{}\begin{matrix}x^2-3x=x-3\\x^2-3x=3-x\end{matrix}\right.\)
<=>\(\left[{}\begin{matrix}x^2-4x+3=0\\x^2-2x-3=0\end{matrix}\right.\)
<=>\(\left[{}\begin{matrix}\left[{}\begin{matrix}x=3\\x=1\end{matrix}\right.\\\left[{}\begin{matrix}x=3\\x=-1\end{matrix}\right.\end{matrix}\right.\)
<=>\(\left[{}\begin{matrix}x=3\\x=1\\x=-1\end{matrix}\right.\)
KL