2 x + 2*x - 4
x^2 + 2*x - 4
2 -4 + x + 2*x
-4 + x^2 + 2*x
/ ___\ / ___\ \x + 1 - \/ 5 /*\x + 1 + \/ 5 /
(x + 1 - sqrt(5))*(x + 1 + sqrt(5))
-4.0 + x^2 + 2.0*x
-4 + x*(2 + x)