\(\left(x-1\right)^2-5=\left(x+2\right)\left(x-2\right)-x\left(x-1\right)\)
\(\Leftrightarrow x^2-2x+1-5=x^2-4-x^2+x\)
\(\Leftrightarrow x^2-3x=0\)
\(\Leftrightarrow x\left(x-3\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x-3=0\Leftrightarrow x=3\end{matrix}\right.\)
Vậy: \(x=0\) hoặc \(x=3\)