Answer:
Date Account titles & Explanation Debit Credit
Sep 04 Purchases (70 backpacks*$50) $3,500
Accounts payable $3,500
Sep 06 Accounts payable $300
Purchase return and allowances $300
Sept 09 Accounts receivable $1,260
(15 backpacks*$84)
Sales $1,260
Sept 13 Accounts payable $3,200
(64 backpacks*$50)
Purchase discount (3,200*2%) $64
Cash (3,200*98%) $3,136