2 x - 4*x + 7
x^2 - 4*x + 7
2 7 + x - 4*x
7 + x^2 - 4*x
/ ___\ / ___\ \x + -2 + I*\/ 3 /*\x + -2 - I*\/ 3 /
(x - 2 + i*sqrt(3))*(x - 2 - i*sqrt(3))
7.0 + x^2 - 4.0*x
7 + x*(-4 + x)