$6x^2-(2x-3)(3x+2)=1_{}$
$⇔6x^2-(6x^2+4x-9x-6)=1_{}$
$⇔6x^2-(6x^2-5x-6)=1_{}$
$⇔6x^2-6x^2+5x+6=1_{}$
$⇔5x+6=1_{}$
$⇔5x=-5_{}$
$⇔x=-1_{}$
$Vậy_{}$ $x=-1_{}$
$b)_{}$ $(x+1)^3-(x-1)(x^2+x+1)-2=0_{}$
$⇔x^3+3x^2+3x+1-(x^3-1)-2=0_{}$
$⇔x^3+3x^2+3x+1-x^3+1-2=0_{}$
$⇔3x^2+3x=0_{}$
$⇔3x.(x+1)=0_{}$
$⇔_{}$ \(\left[ \begin{array}{l}3x=0\\x+1=0\end{array} \right.\) $⇔_{}$ \(\left[ \begin{array}{l}x=0\\x=-1\end{array} \right.\)
$Vậy_{}$ $x_{1}=0;$ $x_{2}=-1$
