Решите пример со всеми сокращениями и т.д зарание
(1 17/18*1 13/14-2 5/8: 1 19/20): (2 25/78-1 1/26)

(1 17/18 · 1 13/14 - 2 5/8 : 1 19/20) : (2 25/78 - 1 1/26) = 1 7/8

1) 1 17/18 · 1 13/14 = 35/18 · 27/14 = (5·3)/(2·2) = 15/4 = 3 3/4

2) 2 5/8 : 1 19/20 = 21/8 : 39/20 = 21/8 · 20/39 = (7·5)/(2·13) = 35/26 = 1 9/26

3) 3 3/4 - 1 9/26 = 3 39/52 - 1 18/52 = 2 21/52

4) 2 25/78 - 1 1/26 = 2 25/78 - 1 3/78 = 1 22/78 = 1 11/39

5) 2 21/52 : 1 11/39 = 125/52 : 50/39 = 125/52 · 39/50 = (5·3)/(4·2) = 15/8 = 1 7/8

ответ: 1 целая 7/8.