Dexter, Inc., collects cash from customers in advance and from other customers after the sale. Journalize the following transactions for Dexter:

a. Accrued revenue. Some customers pay Dexter after Dexter has performed the service for the customer. During 2018, Dexter performed services for $22,000 on account and later received cash of $9,000 on account from these customers.

b. Unearned revenue. A few customers pay Dexter in advance, and Dexter later performs the service for the customer. During 2018, Dexter collected $4,500 cash in advance and later earned $3,000 of this amount.