a) \(x^{50}=xx\)
\(\Leftrightarrow x^{50}=x^2\)
\(\Leftrightarrow x^{50}-x^2=0\)
\(\Leftrightarrow x^2.\left[x^{48}-1\right]=0\)
\(\Leftrightarrow\orbr{\begin{cases}x^2=0\\x^{48}-1=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=0\\x=\pm1\end{cases}}\)
Vậy \(x\in\left\{-1;0;1\right\}\)
b) Tương tự