Why is $59 debited and credited when $49 is the final balance in Allowance for Doubtful Accounts?

Shouldnt the Journal Entry debit and creidit $49?

Step 1: Determine what the current account balance equals. When the estimate is based on receivables (Balance Sheet Approach) the account is the balance sheet portion of the adjusting entry, Allowance for Doubtful Accounts. The existing balance is a $10 debit. Step 2: Determine what the current account balance SHQULD BE. The balance should equal the amount calculated, $49. Step 3: Make an adjusting entry to get from step 1 to step 2