Giải bài toán lớp 6: x mũ 20 = x mũ 12

$x^{20}=x^{12}$
$\Rightarrow x^{20}-x^{12}=0$
$\Rightarrow x^{12}(x^8-1)=0$
$\Rightarrow \left[ \begin{array}{l} x^{12}=0 \\x^8-1=0\end{array} \right .\Rightarrow \left[ \begin{array}{l} x=0 \\x^8=1\end{array} \right .$
$\Rightarrow \left[ \begin{array}{l} x=0 \\x=1\end{array} \right .$