Ответ:

  1. \(7\,050+612\,931=619\,981\).
  2. \(779\,558+1\,223\,398=2\,002\,956\).
  3. \(779\,558+1\,223\,398=2\,002\,956\).
  4. \(59\,697-9\,993=49\,704\).