(2x+6)^2 - 14= -30
(2x + 6)(2x + 6) - 14 = -30
2x^2 + 12x + 12x + 36 = -30
2x^2 + 24x + 36 = -30
2x^2 + 24x = -66
2x^2 + 24x + 66 = 0
x = -24 +- sqrt[24^2 - 4 * 2 * 66]/2 * 2
x = -24 +- sqrt[576 - 528]/4
x = -24 +- sqrt[48]/4
x = -24 +- 4 * sqrt[3]/4
x = -24 + 4 * sqrt[3]/4 or x = -24 - 4 * sqrt[3]/4
I hope this helps.