$(2x^2+3x-6)^2-(3x-2)^2=0$
$⇒[(2x^2+3x-6)+(3x-2)].[(2x^2+3x-6)-(3x-2)]=0$
$⇒(2x^2+3x-6+3x-2).(2x^2+3x-6-3x+2)=0$
$⇒(2x^2+6x-8).(2x^2-4)=0$
\(⇒\left[ \begin{array}{l}2x^2+6x-8=0⇒(x-1)(x+4)=0⇒\left[ \begin{array}{l}x-1=0⇒x=1\\x+4=0⇒x=-4\end{array} \right.\\2x^2-4⇒2x^2=4⇒x^2=2⇒x=±\sqrt2\end{array} \right.\)