So I'm hazarding a guess that the roots would equal 3i/2 and i/2?
Probably completely incorrect.
I really appreciate your help, though!
You have been told exactly what to do and post #6 even gives you the answer (in unsimplified form). I don't understand why (a) you would still be guessing and (b) you would be guessing wrong. You need to take a lot more care with the basic arithmetic - you have made careless and basic mistakes several times now in this thread.