Final answer:
The purchase of merchandise by Adidea Corp. is recorded as a debit to Inventory and a credit to Accounts Payable, reflecting the increase in assets and liabilities.
Step-by-step explanation:
When Adidea Corp. purchases 1,000 units of merchandise on credit from a vendor, the accounting transaction should be recorded in the company's books with a debit to the Inventory account and a credit to the Accounts Payable account. This is an application of the double-entry accounting system, where every transaction affects at least two accounts. The Inventory account represents the company's assets and increases with a debit, reflecting the added value from the newly purchased goods. Conversely, the Accounts Payable account reflects the company's liabilities and increases with a credit because it indicates the amount the company owes to the vendor.