On march 12, masterson company, inc. sold merchandise in the amount of $7,800 to forsythe company, with credit terms of 2/10, n/30. the cost of the items sold is $4,500. masterson uses the gross method of accounting for sales and a perpetual inventory system. on march 15, forsythe returns some of the merchandise. the selling price of the returned merchandise is $600 and the cost of the merchandise returned is $350. the entry or entries that masterson must make on march 15 is