Ответ:

  1. а) \(42:7\cdot8=6\cdot8=48\); \(60\cdot5:10=300:10=30\); \(630:9\cdot3=70\cdot3=210\).
  2. б) \(72:8\cdot3=9\cdot3=27\); \(44:4\cdot2=11\cdot2=22\); \(360:4:3=90:3=30\).
  3. в) \(12\cdot3:9=36:9=4\); \(46:2\cdot3=23\cdot3=69\); \(280:4:7=70:7=10\).
  4. г) \((37+11):24=48:24=2\); \((53-39)\cdot6=14\cdot6=84\); \(49:(71-64)=49:7=7\).