I am preparing an Adjusted trial balance for a class, the answer is at the bottom and I can't get my answer to compare.
Here is where I might have made a mistake.

4 Received $3,950 cash from Alex’s Engineering Co. for the receivable from November.
credit cash
debt acct receivable

should I have credited computer service revenue?

because....
20 Completed a project for Chang Corporation and received $5,625 cash.

here I
credit 5625 to cash
debit computer service revenue

Are both of these right? Seems like the $5,625 was computer service revenue also but it never saw that account. Should I put it there?

This one I really am not sure about..
14 Notified by Alex’s Engineering Co. that Success’s bid of $7,000 on a proposed project has been accepted. Alex’s paid a $1,500 cash advance to Success Systems.

When I first did it I ignored the $5,500 all together and just
credit cash for $1,500
Debit unearned computer service $1,500

I have been looking at this problem for days, it is driving me crazy, and the more I look at it I think I should do something with the $5,500 but if I put it in as unearned service revenue and account receivable the answer is over another $5,500 because I am all ready $4,950 over on my answer.

29 Reimbursed Breeze’s business automobile mileage (600 miles at $0.32 per mile).

credit milage expense 192
debit cash 192

Is that right or is it different when you pay the business mileage and not an employee?

Thanks for any hep!

MaggieMouse

Received $3950: Dr. Cash Cr. Receivable. You don't need to credit revenue because when the service is performed last year, even you didn't get cash, but you debited receivable and credited revenue back then, so it has nothing to do with revenue now, it's all about getting paid.

$5625 was correct, except you have debit and credit wrong. Dr. Cash, Cr. Revenue.

Received $1500 down payment. Dr. Cash, Cr. Unearned Revenue. Service has not been performed yet. Once service is completed, Dr. Unearned revenue Cr. Revenue. Don't need to do anything with $5,500, it's not a recordable activity, no money changing hands, no service performed.

Mileage: when reimbursement happens, you always pay the employee, or contractor, how can you pay the business mileage? Dr. Travel expense Cr. Cash.

You kinda have all your answers starting with credit. I don't know it's a typo or you misunderstanding, but that's incorrect.