2 x - 16 + 28
x^2 - 1*16 + 28
/ ___\ / ___\ 1*\x + 2*I*\/ 3 /*\x - 2*I*\/ 3 /
(1*(x + 2*i*sqrt(3)))*(x - 2*i*sqrt(3))
2 12 + x
12 + x^2
12.0 + x^2