On January $1,$ Wei Company begins the accounting period with a $$42,000$ credit balance in Allowance for Doubtful Accounts.

a$.$ On February $1,$ the company determined that $$9,200$ in customer accounts was uncollectible; specifically, $$2,100$ for Oakley. Company and $$7,100$ for Brookes Company Prepare the journal entry to write off those two accounts.

b$.$ On June $5,$ the company unexpectedly received a $$2,100$ payment on a customer account, Oakley Company, that had previously been written off in part $a.$ Prepare the entries to reinstate the account and record the cash received.