Answer:
Dr. Allowance for doubtful accounts $30,000
Cr. Account receivables $30,000
Explanation:
Allowance for doubtful accounts is an estimate of the receivables which are not expected to be received in future. It is an contra asset account and adjusted against the accounts receivable. On balance sheet Accounts receivable is reported after adjusting the value of allowance for doubtful accounts.
Write off is also adjusted in allowance for doubtful accounts by debiting the allowance for doubtful accounts and crediting the accounts receivables.