Answer:
account receivables 600 debit
allowance for doubful account 600 credit
--to revert the write-off--
cash 600 debit
account receivables 600 credit
--to record the payment from Acme Inc--
Explanation:
The company will revert the write-off of Acme. Inc account and then record a collection as usual
We use the allowance account as previously the company did as follows:
allowance for doubful account 1,200 debit
account receivables 1,200 credit
to write-off the account.
We reverse this by the amount paid by Acme which is 600
Then, we record receiving the cash (debit) and decreasing the account receivable (credit)