Answer:
bad debt expense debit 17,000
allowance for doubful account credit 17,000
Explanation:
again of accounts 5% of AR Â
390,000 x 5% = 19,500 expected allowance
current balance  (2,500 credit)
Adjustment    17,000
When the allowance si calculate using aging of percent on receivables, it should be adjusted by the difference the expected balance with the current balance.
The balance should be 19,500 credit
we have 2,500 credit
we should increase the allowance by the difference so it balance after the adjustment equals the expected balance.