[tex]\sqrt{x + 12} = x + 2[/tex]
[tex](\sqrt{x + 12})^{2} = (x + 2)^{2}[/tex]
[tex]x + 12 = x^{2} + 4x + 4[/tex]
[tex]12 = x^{2} + 3x + 4[/tex]
[tex]0 = x^{2} + 3x - 8[/tex]
[tex]x = \frac{-(3) \± \sqrt{(3)^{2} + 4(1)(-8)}}{2(1)}[/tex]
[tex]x = \frac{-3 \± \sqrt{9 + 4(-8)}}{2}[/tex]
[tex]x = \frac{-3 \± \sqrt{9 - 32}}{2}[/tex]
[tex]x = \frac{-3 \± \sqrt{-23}}{2}[/tex]
[tex]x = \frac{-3 \± i\sqrt{23}}{2}[/tex]