Пошаговое объяснение:
1) 2 1/2 + 1 1/3 = 2 3/6 +
1 2/6 = 3 5/6
2) 3 5/6 : 1/6 = 23/6 * 6/1 = 23/1 = 23
3) 23 - 5 3/7 = 22 7/7 - 5 3/7 = 17 4/7
