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