please answer a&b!! also please write out answers I can not read typed ones! thank you

Sandhill Company had a $840 credit balance in Allowance for Doubtful Accounts at December 31, 2020, before the current year's provision for uncollectible accounts. An aging of the accounts receivable revealed the following: Estimated Percentage Uncollectible $144.000 1 % 24,000 3 % Current Accounts 1-30 days past due 31-60 days past due 61-90 days past due 12,000 12,000 12 % Over 90 days past due 8.400 30 % Total Accounts Receivable $200,400 (a) Prepare the adjusting entry on December 31, 2020, to recognize bad debt expense. (Credit account titles are automatically Indented when the amount is entered, Do not indent manually. List all debit entry before credit entry) Account Titles and Explanation Debit Credit Bad Debt Expense Allowance for Doubtful Accounts (b) Assume the same facts as above except that the Allowance for Doubtful Accounts account had a $600 debit balance before the current year's provision for uncollectible accounts. Prepare the adjusting entry for the current year's provision for uncollectible accounts. (Credit account titles are automatically indented when the amount is entered. Do not indent manually. List all debit entry before credit entry) Account Titles and Explanation Debit Credit Bad Debt Expense Allowance for Doubtful Accounts