This is very easy...if u need help on this just imagine the negative numbers as subtraction instead. So for example (This is very hard to explain lol) 6 + -4. Don't do 6 + 4. Do 6 - 4. That will equal 2 right? Ok, do the same to the rest. (Just use google for a better explanation lol. I'm not really good at explaining stuff lmbo) Hope this helps you even tho the other person answered. But, at least i helped you (Not really tho, lol)