Merchandise Inventory after trial balance 985.
Merchandise Inventory at end of period 124,115. What is adjusting entry?

Supplies after trial balance 550.
Supplies at end of period 975.
What is adjusting entry?

Adjusting entries are journal entries usually made at the end of an accounting period to allocate income and expenditure to the period in which they actually occurred.

You have to know the account balance of supplies at the end of the period, which you do not have. You should have this information in your problem or you should have the amount of purchases which will be added to your beginning account balance to get your ending account balance.

Your adjusting entry amount will be for the difference between your ending account balance and your actual account balance. Your adjusting entry will be:
Debit Cost of Goods Sold for the difference between your ending account balance and your actual inventory balance
Credit Merchandise Inventory for the same amount