Answer :
[tex]2x^2-2x-12=0\\
2(x^2-x-6)=0\\
2(x^2-3x+2x-6)=0\\
2(x(x-3)+2(x-3))=0\\
2(x+2)(x-3)=0\\
x=-2 \vee x=3[/tex]
[tex]2x^2-2x-12=0\\\\2x^2+4x-6x-12=0\\\\2x(x+2)-6(x+2)=0\\\\(x+2)(2x-6)=0\iff x+2=0\ \vee\ 2x-6=0\\\\x=-2\ \vee\ x=3[/tex]
