1.
а) 1 5/7 : 1 1/7 = 12/7 × 7/8 = 3/2 = 1 1/2
ответ: 1 1/2
б) 3 1/5 : 2 2/15 = 16/5 × 15/32 = 3/2 = 1 1/2
ответ: 1 1/2
в) 5 2/3 : 1/3 - 1 7/12 × 6 = 7 1/2
1) 5 2/3 : 1/3 = 17/3 × 3/1 = 17/1 = 17
2) 1 7/12 × 6 = 19/2 = 9 1/2
3) 17 - 9 1/2 = 15/2 = 7 1/2
ответ: 7 1/2
4.
1/6 х + 5/12 х = 8,4
7/12 х = 8,4
х = 42/5 × 12/7
х = 72/5 = 14 2/5
ответ: х = 14 2/5