It appears you want (x-3)(x-2i)(x+2i)
Once again you have a garbled question. Either name the roots or the factors. You have a mix of both.
use the complex zeros to give fully factored form, the first factor needs a x in it : (-3) (-2i)(x+2i)
2 answers
The question is how you go from x^2+4, to -2i.