7 2/7 : 1 5/21 + (4 3/13 * 14/15 - 3 1/3) = 6 1/2
1) 4 3/13 * 14/15 = 55/13 * 14/15 = 770/195 = 3 37/39
2) 3 37/39 - 3 1/3 = 3 37/39 - 3 13/39 = 24/39 = 8/13
3) 7 2/7 : 1 5/21 = 51/7 : 26/21 = 51/7 * 21/26 = 153/26 = 5 23/26
4) 5 23/26 + 8/13 = 5 23/26 + 16/26 = 5 39/26 = 6 13/26 = 6 1/2
(2 1/2 : 10 + 10 : 2 1/2 - 2 1/6) * 36/125 = 3/5
1) 2 1/2 : 10 = 5/2 * 1/10 = 5/20 = 1/4
2) 10 : 2 1/2 = 10 : 5/2 = 10 * 2/5 = 20/5 = 4
3) 1/4 + 4 = 4 1/4
4) 4 1/4 - 2 1/6 = 4 3/12 - 2 2/12 = 2 1/12
5) 2 1/12 * 36/125 = 25/12 * 36/125 = 3/5