Answer :
[tex]Formula\ for\ absolute\ value\\\\
|a|=a,\ for\ a \geq 0\\ or\\|a|=-a,\ for\ a<0
\\\\
-3|2x+6|=-12\\
-3(2x+6)=-12\ \ \ or\ \ \ -3(-2x-6)=-12\\
-6x-18=-12\ \ \ or\ \ \ 6x+18=-12\\
-6x=6\ \ \ or\ \ \ 6x=-30\\
x=-1\ \ \ or \ \ \ x=-5\\\\Solutions\ are\ -1 and\ -5.[/tex]