Answer:
Debit Accounts Receivable, $3,000; credit Roofing Fees Revenue, $3,000.
Explanation:
The revenue recognition principle provides that revenue is recognized when it is earned, and  when it is realized or realizable . Revenue is earned when the earnings process is substantially complete.  Revenue is realized when goods and services are exchanged for cash or claims to cash. Â
In this case, on December 31 the service has been completed. The adjusting entry the company would need to make is:
-Make a debit in the account of Accounts Receivable (asset account), for $3,000.
-Make a credit in the account of Roofing Fees Revenue (revenue account), for$3,000.