Ответ:

  1. \(3 + 1 = 4\)
  2. \(4 - 3 = 1\)
  3. \(4 - 1 = 3\)
  4. \(10 - 1 = 9\)
  5. \(9 - 1 = 8\)
  6. \(8 - 1 = 7\)