\(\Leftrightarrow x^2-1=+-\left(x-1\right)\)
\(\Leftrightarrow\left\{{}\begin{matrix}x^2-1=x-1\\x^2-1=1-x\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x^2-x=0\\x^2+x-2=0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x\left(x-1\right)=0\\\left(x-1\right)\left(x+2\right)=0\end{matrix}\right.\)
\(\Leftrightarrow x=\left(0,1,-2\right)\)
Mà \(x^2-1\ge0\Leftrightarrow x^2\ge1\Leftrightarrow\left[{}\begin{matrix}x\le-1\\x\ge1\end{matrix}\right.\).Vậy x=(0,-2)