$58,000 is the amount of adjusting entry for bad debts at december 31st. To calculate the adjusting entry for bad debts at december 31st we need to subtract the aloowance for doubtful accounts to accounts receivable which is $128,000 and $70,000 respectively. So 128,000 - 70,000 = $58,000. The answer in this question is $58,000.