Ta có : $(x-1)^{x+2}=(x-1)^{x+6}$
$⇔(x-1)^{x+2}.[(x-1)^4-1]=0$
$⇔\(\left[ \begin{array}{l}(x-1)^{x+2}=0\\(x-1)^4-1=0\end{array} \right.$
$⇔\(\left[ \begin{array}{l}x-1=0\\(x-1)^4=1\end{array} \right.$
$⇔\(\left[ \begin{array}{l}x=1\\x=2\\x=0\end{array} \right.$
