9. The post-closing trial balance includes only income statement accounts 10. In a merchandising firm, sales minus cost of goods sold equal income before income taxe 11. In specifying credit terra, 2/10, 1/30 mean that one halt of the involce most be paid in 10 days, with the net balance due in 30 days. 9. The post-closing trial balance includes only income statement accounts 10. In a merchandising firm, sales minus cost of goods sold equal income before income taxe 11. In specifying credit terra, 2/10, 1/30 mean that one halt of the involce most be paid in 10 days, with the net balance due in 30 days