Please someone teach me accouting question!!?

Question

I do not understand which journal i should put these question.
Genral, Sale, Cash Receipts, Purchases, Cash Payments Journals.
1, Paid ~~~
2, Invest ~~~
3, Purchased~~
4, Received
5, Completed a five day project for Alexs engineering Co. and builled it $6,500, which is the total price of $9,000 less the advance payment of $2,500
6, Sold merchandises with a retail value of $6,000 and a cost of $4,080 to Chang Corp., invoice dated January.

I can write everything here, so if someone help me to teach accounting quesiton, please contact me!! [e-mail]

Answer 1

1, Paid ~~~
Anything you paid would be recorded in the Cash Payments Journal.

2, Invest ~~~
If you invested in something and haven't paid for it yet, it would go into the General Journal. If you've paid for it, it'd go into the Cash Payments Journal.

3, Purchased~~
Purchases go into the Purchases Journal.

4, Received
Receipts go into the Cash Receipts Journal.

5, Completed a five day project for Alexs engineering Co. and builled it $6,500, which is the total price of $9,000 less the advance payment of $2,500
If the project was worth $9,000, your total bills should be $9,000. I hope you've previously billed $2,500. Assuming you did, now when you bill the balance $6,500, your entry:
Dr Unearned revenue $2,500
Dr A/cs receivable $6,500
Cr Service revenue $9,000

6, Sold merchandises with a retail value of $6,000 and a cost of $4,080 to Chang Corp., invoice dated January.
Dr A/cs receivable $6,000
Cr Sales $6,000

Dr COGS $4,080
Cr Merchandise inventory $4,080