Ответ:

13 - (67/12 - 19/15) = 780/60 - (1005/60 - 228/60) = (780-777)/60 =  1/20

11 - (139/21 + 3/14) = 462/42 - (278/42 + 9/42) = (462 - 287)/42 = 25/6

15/2 - (453/50 - 132/25) = 375/50 - (453/50 - 264/50) = (375 - 189)/50 = 93/25

15/16 - (1/3 + 3/8) = 45/48 - (16/48 + 18/48) = (45-34)/48 = 11/48

5/8 - (1/3 + 1/6) = 15/24 - (8/24 + 4/24) = (15-13)/24 = 1/12

14/15 - (2/3 + 1/5) = 14/15 - (10/15 + 3/15) = (14-13)/15 = 1/15

16/21 - (1/6 + 2/7) = 32/42 - (7/42 + 12/42) = (32-19)/42 = 13/42

12/13 - (2/5 + 9/65) = 60/65 - (26/65 + 9/65) = (60-35)/65 = 5/13

7/8 - (1/4 + 2/5) = 35/40 - (10/40 + 16/40) = (35-26)/40 = 9/40

(25/28 - 5/14) - (5/7 - 1/4) = (25/28 - 10/28) - (20/28 - 7/28) = (15-13)/28 = 1/14

Пошаговое объяснение:

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