2 - x + 3*x + 4
-x^2 + 3*x + 4
(x + 1)*(x - 4)
2 4 - x + 3*x
4 - x^2 + 3*x
4.0 - x^2 + 3.0*x
-(1 + x)*(-4 + x)
4 + x*(3 - x)