-2
Пошаговое объяснение:
1) 8/9 - 7/12 = 32/36 - 21/36 = 11/36
2) 4. 10/11 * 11/36 = 54/11 * 11/36 = 54/36 = 1. 18/36 = 1. 1/2
3) 9 : 2. 4/7 = 9 : 18/7 =
9 * 7/18 = 1*7 / 2 = 7/2 =
3. 1/2
4) 1. 1/2 - 3. 1/2 = -2
