Seven years ago, elise damato started a business specializing in dog walking and dog grooming. after the first year, her pet food supplier started giving elise a cash discount of 2.25% on any amount paid within 15 days of the invoice date. on october 25, elise bought pet food costing $1,064. on november 8, elise paid $800 on the purchase. compute the unpaid balance. (this problem involves the partial payment of an invoice within the discount period.)