Prepare journal entries to record each of the following sales transactions of EcoMart Merchandising. EcoMart uses a perpetual inventory system and the gross method. Oct. 1 Sold merchandise for $1,500, with credit terms n/30, invoice dated October 1 . The cost of the merchandise is $900. 6 The customer in the October 1 sale returned $150 of merchandise for full credit. The merchandise, which had cost $90, is returned to inventory. 9 Sold merchandise for $700 cash. Cost of the merchandise is $450. 30 Received payment for the amount due from the October 1 sale less the return on October 6