4 3 2 x - 6*x + 13*x - 12*x + 4
x^4 - 6*x^3 + 13*x^2 - 12*x + 4
1*(x - 1)*(x - 2)
(1*(x - 1))*(x - 2)
4.0 + x^4 + 13.0*x^2 - 6.0*x^3 - 12.0*x
2 2 (-1 + x) *(-2 + x)
(-1 + x)^2*(-2 + x)^2