Solve LaTeX: \displaystyle x^{2} - 24 x + 340 = 0

Using the quadratic formula gives LaTeX: \displaystyle x=\frac{ -(-24)\pm \sqrt{ (-24)^2 -4(1)(340) } }{ 2(1) }
Simplifying gives LaTeX: \displaystyle x=\frac{ 24 \pm \sqrt{ -784 } }{ 2 } = 12 \pm 14 i