2 x - 4*x - 7
x^2 - 4*x - 7
2 -7 + x - 4*x
-7 + x^2 - 4*x
/ ____\ / ____\ \x + -2 + \/ 11 /*\x + -2 - \/ 11 /
(x - 2 + sqrt(11))*(x - 2 - sqrt(11))
-7 + x*(-4 + x)
-7.0 + x^2 - 4.0*x