2 x + 4*x + 13
x^2 + 4*x + 13
2 13 + x + 4*x
13 + x^2 + 4*x
(x + 2 + 3*I)*(x + 2 - 3*I)
(x + 2 + 3*i)*(x + 2 - 3*i)
13.0 + x^2 + 4.0*x
13 + x*(4 + x)