8.2/5-2.4/9

2,5+7,5/8

5,1/4-1,2/3

8 2/5 - 2 4/9 = 8 18/45 - 2 20/45 = 7 63/45 - 2 20/45 = 5 целых 43/45

2 1/2 + 7 5/8 = 2 4/8 + 7 5/8 = 9 9/8 = 10 целых 1/8

5 1/4 - 1 2/3 = 5 3/12 - 1 8/12 = 4 15/12 - 1 8/12 = 3 целых 7/12