Solve LaTeX: \displaystyle x^{2} + 16 x + 100 = 0

Using the quadratic formula gives LaTeX: \displaystyle x=\frac{ -(16)\pm \sqrt{ (16)^2 -4(1)(100) } }{ 2(1) }
Simplifying gives LaTeX: \displaystyle x=\frac{ -16 \pm \sqrt{ -144 } }{ 2 } = -8 \pm -6 i