(это в комментариях) номер 1 1/2+1/3, 3/7+5/8, 1/10-1/13, 1/2-1/11 номер 2 3/8+4/16, 5/24+7/48, 7/9-4/27, 2/15-1/30 номер 3 7/33-3/77, 6/15+1/56, 4/49-5/63

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1.

1/2+1/3 = 3/6 + 2/6 = 5/6,
3/7+5/8 = 24/56 + 35/56 = 59/56 = 1 3/56,
1/10-1/13 = 13/130 - 10/130 = 3/130,
1/2-1/11 = 11/22 - 2/22 = 9/22,

2.

3/8+4/16 = 6/16 + 4/16 = 10/16 = 5/8,
5/24+7/48 = 10/48 + 7/48 = 17/48,
7/9-4/27 = 21/27 - 4/27 = 17/27,
2/15-1/30 = 4/30 - 1/30 = 3/30 = 1/10,

3.

7/33-3/77 = 49/231 - 9/231 = 40/231,
6/15+1/56 = 336/840 + 15/840 = 351/840 = 117/280,
4/49-5/63 = 36/441 - 35/441 = 1/441