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Brooks Company purchases debt investments as trading securities at a cost of $66,000 on December 27. This is its first and only purchase of such securities. At December 31, these securities had a fair value of $72,000.

Brooks sells a portion of its trading securities (costing $3,000) for $4,000 cash. Analyze each transaction above by showing its effects on the accounting equationspecifically, identify the accounts and amounts (including + or ) for each transaction.