After I pay off 3 credit cards should I close them or keep them open? I want to build more credit.?

I was unemployed for a while and wasn't able to keep up with payments so now my credit is not great. I have 2 cards that have been closed but I have been given assistance by the creditors to reduce payments and interest. So I have those 2 cards that show negatively on my credit report and the 3 cards still open that I am going to pay off that I mentioned in my question.