$\text{$x^{17}$ = x}$
$\text{$x^{17}$ - x = 0}$
$\text{x($x^{16}$ - 1) = 0}$
$\text{⇒ \(\left[ \begin{array}{l}x=0\\x^{16} - 1 = 0\end{array} \right.\) }$
$\text{⇒ \(\left[ \begin{array}{l}x=0\\x^{16} = 1\end{array} \right.\) }$
$\text{⇒ \(\left[ \begin{array}{l}x=0\\x= 1\end{array} \right.\) }$
$\text{Vậy x ∈ {0; 1}}$