I would like to ask a question in management accounting. I did get the right result BUT I DO NOT UNDERSTAND for what reason do we have here "accounts payable and accounts receivable", because they are quite useless, as I have got the right result without using them... Explain please whats is the role of having this accounts in this task.

4.- An auditor for the Internal Revenue Service is trying to reconstruct some partially destroyed records of two taxpayers. Concepts Accounts receivable, 31/12/0x Cost of goods sold Accounts payable, 01/01/0x Accounts payable, 31/12/0x Finished goods inventory, 31/12/0x Gross margin Work in process, 01/01/0x Case 1 In thousands $ 6.000 A 3.000 1.800 B 11.300 0 Case 2 In thousands $ 2.100 20.000 1.700 1.500 5.300 800 Page 3/6 Created by Amparo Ayuso Work in process, 31/12/0x Finished goods inventory 01/01/0x Direct material used Direct manufacturing labor Indirect manufacturing costs Purchases of direct material Revenues Accounts receivable 01/01/0x 4.000 8.000 3.000 7.000 9.000 32.000 2.000 3.000 4.000 12.000 5.000 D 7.000 31.800 1.400 Required: For each of the cases in the accompanying list, find the unknowns designated by the letters A trough D. (using the T account format shown in the theory slides)