using the perpetual inventory system, journalize the entries for the following selected transactions: a. Sold merchandise on account, for $12,000. The cost of the merchandise sold was $6,500. (3/15,n/45) b. The customer paid within the discount period for transactions. (a) c. Sold merchandise for $2,900. The cost of the merchandise sold was $1,700. Sales tax is 7%. d. Sold merchandise on account for $1200. The cost of the merchandise was $800. (5/20,n/60. e. The customer returned $600 of merchandise from transactions (d). The cost of this merchandise was $400. f. The customer made the payment on the remaining merchandise after the discount period expired.