Answer
{$-2+2\sqrt 3,-2-2\sqrt 3$}
Work Step by Step
Given: $3(x+2)^2=36$
This can be written as: $(x+2)=12$
Apply The Square Root Property.
or, $x+2=\sqrt{12}$
or, $x+2=\pm (2\sqrt 3)$
or, $x=-2+2\sqrt 3,-2-2\sqrt 3$
Hence, solution set is $x=${$-2+2\sqrt 3,-2-2\sqrt 3$}