Ответ:

  1. \(82\cdot7=(80+2)\cdot7=80\cdot7+2\cdot7=560+14=574\).
  2. \(97\cdot9=(100-3)\cdot9=100\cdot9-3\cdot9=900-27=873\).
  3. \(63\cdot8=(60+3)\cdot8=60\cdot8+3\cdot8=480+24=504\).
  4. \(78\cdot6=(80-2)\cdot6=80\cdot6-2\cdot6=480-12=468\).

Ответ: 574; 873; 504; 468.