1) -1/6 - 1/10 - 1/15 = -5/30 - 3/30 - 2/30 = -10/30 = -1/3
2) 1/6 - 1/15 + 1/10 = 5/30 - 2/30 + 3/30 = 6/30 = 1/5
3) 1/3 : 1/5 = 1/3 * 5 = 5/3
4) 0,5 + 0,25 = 0,75
5) -1/3 - 1/5 = -5/15 - 3/15 = -8/15
6) 0,75 - 8/15 = 3/4 - 8/15 = 45/60 - 32/60 = 13/60
7) 0,25 - 1/6 = 1/4 - 1/6 = 3/12 - 2/12 = 1/12
8) 13/60 : 1/12 = 13/60 * 12 = 13/5
9) 5/3 : 13/5 = 5/3 * 5/13 = 25/39
ответ : 25/39