Ответ:

Пошаговое объяснение:

1) 9. 1/4 - 8. 2/3 = 9. 3/12 - 8. 8/12 = 8. 15/12 - 8. 8/12 = 7/12

2) 7/12 * 1. 5/7 = 7/12 * 12/7 = 1/1 * 1/1 = 1

3) 4. 2/9 - 2. 5/6 = 4. 4/18 - 2. 15/18 = 3. 22/18 - 2. 15/18 = 1. 7/18

4) 1. 7/18 : 1. 1/9 = 25/18 : 10/9 = 25/18 * 9/10 = 5/2 * 1/2 = 5/4 = 1. 1/4

5) 1 + 1. 1/4 = 2. 1/4