Answer:
1)
November 17, 100 units sold to Thomas Company on account, credit terms 2/1, n/30
Dr Accounts receivable 42,000
  Cr Sales revenue 42,000
November 26, invoice collected from Thomas Company
Dr Cash 41,160
Dr Sales discounts 840
  Cr Accounts receivable 42,000
2)
November 17, 100 units sold to Thomas Company on account, credit terms 2/1, n/30
Dr Accounts receivable 42,000
  Cr Sales revenue 42,000
December 15, invoice collected from Thomas Company
Dr Cash 42,000
  Cr Accounts receivable 42,000
3)
November 17, 100 units sold to Thomas Company on account, credit terms 2/1, n/30
Dr Accounts receivable 41,160
  Cr Sales revenue 41,160
November 26, invoice collected from Thomas Company
Dr Cash 41,160
  Cr Accounts receivable 41,160
4)
November 17, 100 units sold to Thomas Company on account, credit terms 2/1, n/30
Dr Accounts receivable 41,160
  Cr Sales revenue 41,160
December 15, 2016, invoice collected from Thomas Company
Dr Accounts receivable 840
  Cr Sales discounts forfeited 840
Dr Cash 42,000
  Cr Accounts receivable 42,000