What are the typical system interfaces of a point-of-sale system that need to be taken into account in designing the pos system?

Enzo’s balance sheet for the month of july is shown. enzo’s balance sheet (july 2013) assets liabilities cash $600 credit card $4,000 investments $500 student loan $2,500 house $120,000 mortgage $80,000 car $6,000 car loan $2,000 total $127,100 total $88,500 which expression finds enzo’s net worth?