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