$a)_{}$ $x^2-x=0_{}$
$⇔x.(x-1)=0_{}$
$⇔_{}$ \(\left[ \begin{array}{l}x=0\\x-1=0\end{array} \right.\) $⇔_{}$ \(\left[ \begin{array}{l}x=0\\x=1\end{array} \right.\)
$Vậy_{}$ $x_{1}=0;$ $x_{2}=1$
$b)_{}$ $(x+2)(x-3)-x-2=0_{}$
$⇔(x+2)(x-3)-(x+2)=0_{}$
$⇔(x+2)(x-3-1)=0_{}$
$⇔(x+2)(x-4)=0_{}$
$⇔_{}$ \(\left[ \begin{array}{l}x+2=0\\x-4=0\end{array} \right.\) $⇔_{}$ \(\left[ \begin{array}{l}x=-2\\x=4\end{array} \right.\)
$Vậy_{}$ $x_{1}=-2;$ $x_{2}=4$
