2 x + 6*x - 11
x^2 + 6*x - 11
2 -11 + x + 6*x
-11 + x^2 + 6*x
/ ___\ / ___\ \x + 3 - 2*\/ 5 /*\x + 3 + 2*\/ 5 /
(x + 3 - 2*sqrt(5))*(x + 3 + 2*sqrt(5))
-11 + x*(6 + x)
-11.0 + x^2 + 6.0*x