Ответ:

  1. XLII = 40 + 2 = 42.
  2. XXVII = 20 + 7 = 27.
  3. XL = 50 − 10 = 40.
  4. LXX = 50 + 20 = 70.
  5. CXL = 100 + 40 = 140.
  6. DCC = 500 + 200 = 700.