Ответ:

  1. \(8/9=16/18<17/18\), значит, \(8/9<17/18\).
  2. \(6/7=18/21>17/21\), значит, \(6/7>17/21\).
  3. \(7/12=35/60<44/60=11/15\), значит, \(7/12<11/15\).
  4. \(5/9=35/63<36/63=4/7\), значит, \(5/9<4/7\).
  5. \(7/10=21/30<26/30=13/15\), значит, \(7/10<13/15\).
  6. \(7/8=21/24<22/24=11/12\), значит, \(7/8<11/12\).