1. 4/21
2.55/56
3.31/9
4.93/20
1 - 17/23 = 23/23 - 17/23= 6/23
Пошаговое объяснение:
1 - 1/56 = 56/56 - 1/56 = 55/56
4 - 5/9 = 3 9/9- 5/9= 3 4/9
5- 7/20 = 4 20/20 - 7/20 = 4 13/20
