It isn't very clear to me what I'm supposed to do. I've learned how to do trial balance & financial statements but when I add things up here they clearly don't match. However, the ones where they only post on one side my answers are right and where I get postings on both sides my answers are incorrect.

Your answer is partially correct. Calculate the account balance for the following accounts: Cash Cr. Dr. 510 8,890 820 505 9,100 6,885 5,460 10,645 16280 Bal. 26535 Bal. Service Revenue Cr. Dr. 9,690 3,260 4,590 1,070 Bal. 18610 Accounts Payable Cr. Dr. 6,870 1,750 505 6,885 2,550 9420 Bal. 9140 Salary Expense Cr. Dr. 4,640 560 3,830 435 Bal. 9465