Пошаговое объяснение:
1) -2/9 + (2/9 - 3/4) =
-2/9 + 2/9 - 3/4 = -3/4
2) 4/7 - (5/11 - 3/7) =
4/7 - 5/11 + 3/7 = 7/7 - 5/11 = 1 - 5/11 = 11/11 - 5/11 = 6/11
3) 3. 5/6 + (-5/6 - 1/7) =
3. 5/6 - 5/6 - 1/7 = 3 - 1/7 = 2. 7/7 - 1/7 = 2. 6/7
4) 3/8 - (1/9 - 5/8) =
3/8 - 1/9 + 5/8 = 8/8 - 1/9 = 1 - 1/9 = 9/9 - 1/9 = 8/9
5) 2. 3/4 - (1. 1/4 + 5. 1/2) = 2. 3/4 - 1. 1/4 - 5. 1/12 =
1. 2/4 - 5. 1/12 = 1. 6/12 - 5. 1/12 = 1. 6/12 - 4. 13/12 = -3. 7/12
6) 6. 5/8 - (1. 3/4 - 2. 3/8) = 6. 5/8 - 1. 3/4 + 2. 3/8 =
8. 8/8 - 1. 3/4 = 8. 8/8 - 1. 6/8 = 7. 2/8 = 7. 1/4
