So I'm having a hard time figuring out what exact type of transactions each of these are.

May 4 Real estate commissions billed to clients amount to $4,000

7 Received a bill for $500 for advertising for the current month

10 Received a check for $3,000 from a client in payment on account for the commissions
Billed in transaction 4.


My professor never really discussed with us how to journalize bills, so I think that's where my trouble is coming from. Any help would be greatly appreciated! Thank you!