2 - x + 2*x + 3
-x^2 + 2*x + 3
2 3 - x + 2*x
3 - x^2 + 2*x
(x + 1)*(x - 3)
3.0 - x^2 + 2.0*x
-(1 + x)*(-3 + x)
3 + x*(2 - x)