3 2 z - 2*z + z - 2
z^3 - 2*z^2 + z - 2
3 2 -2 + z + z - 2*z
-2 + z + z^3 - 2*z^2
(x - 2)*(x + I)*(x - I)
((x - 2)*(x + i))*(x - i)
/ 2\ \1 + z /*(-2 + z)
(1 + z^2)*(-2 + z)
-2.0 + z + z^3 - 2.0*z^2
-2 + z*(1 + z*(-2 + z))