\(x^{2005}=x\Leftrightarrow x^{2005}-x=0\Leftrightarrow x\left(x^{2004}-1\right)=0\)
\(\Leftrightarrow\left\{{}\begin{matrix}x=0\\x^{2004}-1=0\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}x=0\\\left\{{}\begin{matrix}x=1\\x=-1\end{matrix}\right.\end{matrix}\right.\) vậy \(x=0;x=1;x=-1\)
