Ответ:

  1. а) \(3\,587\,357\,285 + 12\,542\,284\,367 = 16\,129\,641\,652\).
    \(16\,129\,641\,652 + 2\,060\,438\,247 = 18\,190\,079\,899\).
  2. б) \(728\,405\,247\,961 + 33\,860\,632\,506 = 762\,265\,880\,467\).
    \(762\,265\,880\,467 + 87\,606\,029\,453 = 849\,871\,909\,920\).