Please explain how this August 29th journal entry is wrong. When I use the check my work function says the "sales account" & "accounts receivable" account is wrong and their numbers are too. Also, what does just n/10 mean? what kind of deal is that?

Aug. 29) Received Wilson's cash payment for the amount due from the August 19 sale less the price allowance from August 22 Note: Enter debits before credits. Account Title Credit Date Debit Cash Aug 29 3,700 Sales discounts 500 Accounts receivable - Wilson 4,200 Aug. 19 Sold merchandise to Wilson Co. for $4,200 under credit terms of n/10, FOB shipping point, invoice dated August 19. The merchandise had cost $2,100. Aug. 22 Wilson requested a price reduction on the August 19 sale because the merchandise did not meet specifications Mitchell's sent Wilson a $500 credit memorandum toward the $4,200 invoice to resolve the issue. Aug. 29 Received Wilson's cash payment for the amount due from the August 19 sale less the price allowance from August 22. Aug. 30 Paid Walker Company the amount due from the August 1 purchase