You can put this solution on YOUR website! All you have to do is Foil like normal and then add the like terms.
When you foil you get
-32 +4i-72i+8i^2
Add like terms
-32-68i+8i^2
i^2 is really -1 so you get
-32-68i-8
Add like terms again
-40-68i
and thats the answer