Help with the RED Xs

The following transaction occurred between the Decker Company and Mann Stores, Inc., during March: Decker sold $ 18, 200 worth of merchandise ($13, 800 cost) to Mann Stores with terms of 2/10, n/30. Mann Stores paid freight charges on the shipment from Decker Company, $250. Mann Stores returned $1, 250 of the merchandise ($850 cost) shipped on March 8. Decker received full payment for the net amount due from the March 8 sale. Mann Stores returned goods that had been billed originally at $500 ($400 cost). Decker issued a check for $490. Prepare the necessary journal entries for (a) the books of Decker Company and (b) the books of Mann Stores, Inc. Assume that both companies use the perpetual inventory system