5/6 + 3/8 = 20/24 + 9/24 = 29/24 = 1 5/24,
19/31 - 11/15 = 285/465 - 341/465 = -56/465,
21/22 - 3/55 = 105/110 - 6/110 = 99/110 = 9/10,
5/42 + 10/63 = 15/126 + 20/126 = 35/126 = 5/18,
11/21 - 2/35 = 55/105 - 6/105 = 49/105,
5/24 + 7/60 = 25/120 + 14/120 = 39/120 = 13/40