Subtract 8x from both sides to get [tex] x^{2} -8x+20=0[/tex]
Then using the quadratic formula: [tex]x= \frac{-b+/- \sqrt{ b^{2}-4ac } }{2a} [/tex]
Substitute a = 1, b = -8, and c = 20
[tex]x= \frac{8+/- \sqrt{64-4(1)(20)} }{2(1)} [/tex] -(-8) = 8 and (-8)^2 = 64
[tex]x=4+/-2i[/tex]