№ 551.
1) 4 2/3 - 2/3 = 4
2) 9 5/9 - 5/9 = 9
3) 25 21/31 - 21/31 = 25
4) 75 41/69 - 3 41/69 = 72
5) 40 5/106 - 11 5/106 = 29
№ 552.
1) 2 7/9 - 1/3 = 2 7/9 - 3/9 = 2 4/9
2) 3 4/5 - 2/3 = 3 12/15 - 10/15 = 3 2/15
3) 4 5/6 - 2 1/3 = 4 5/6 - 2 2/6 = 2 3/6 = 2 1/2