Ответ:

  1. \(170-140=30\).
  2. \(680-400=280\).
  3. \(67\,005-58\,906=8\,099\).
  4. \(39\,067-8\,471=30\,596\).
  5. \(2\,223\,222\,222-987\,654\,321=1\,235\,567\,901\).
  6. \(1\,284\,567\,890-45\,678\,910=1\,238\,888\,980\).

Ответ: 30; 280; 8099; 30 596; 1 235 567 901; 1 238 888 980.