I'm pretty lost here.. and simply unclear on what exactly I should be doing.

If someone could walk me through the steps to getting this answer, I'd extremely appreciate it.

Find the roots of the polynomial equation:

I've used synthetic division to find -2 as a root and get the depressed polynomial .. and then used the quadratic formula to find what I think are the correct zeroes of that equation. (which are: 1+i, 1-i.)

Here's where I'm unsure of what to do. Thanks for your help!