5.15. Вычислите: а) 24 − 19, · 8, + 12, − 17, : 5; б) 42 − 33, · 6, + 27, − 9, : 8; в) 57 − 49, · 7, + 14, − 28, : 7; г) 72 − 67, · 6, + 24, − 20, : 17; д) 66 − 59, · 7, + 17, − 38, : 4.

1. а) \(24-19=5\), \(5\cdot8=40\), \(40+12=52\), \(52-17=35\), \(35:5=7\).
2. б) \(42-33=9\), \(9\cdot6=54\), \(54+27=81\), \(81-9=72\), \(72:8=9\).
3. в) \(57-49=8\), \(8\cdot7=56\), \(56+14=70\), \(70-28=42\), \(42:7=6\).
4. г) \(72-67=5\), \(5\cdot6=30\), \(30+24=54\), \(54-20=34\), \(34:17=2\).
5. д) \(66-59=7\), \(7\cdot7=49\), \(49+17=66\), \(66-38=28\), \(28:4=7\).

Ответ: а) 7; б) 9; в) 6; г) 2; д) 7.