Ответ:

  1. \(68\,451-25\,508=42\,943\).

  2. \(24\,084-23\,852=232\).

  3. \(56\,431-7\,025=49\,406\).

  4. \(80\,004\,874-60\,340\,285=19\,664\,589\).

  5. \(4\,723\,068-3\,847\,946=875\,122\).

  6. \(2\,000\,000\,000-478\,249\,546=1\,521\,750\,454\).