[tex]3(x+4)^2-81=0\ \ \ |+81\\\\3(x+4)^2=81\ \ \ |:3\\\\(x+4)^2=27\to x+4=\pm\sqrt{27}\ \ \ \ |-4\\\\x=\pm\sqrt{27}-4\\\\x=\pm\sqrt{9\cdot3}-4\\\\x=\pm\sqrt9\cdot\sqrt3-4\\\\x=-3\sqrt3-4\ \vee\ x=3\sqrt3-4[/tex]
[tex] 3(x+4)^2-81=0\\3(x+4)^2=81\\(x+4)^2=27\\x+4=\sqrt{27} \vee x+4=-\sqrt{27}\\x=-4+3\sqrt3 \vee x=-4-3\sqrt3 [/tex]
