(3 1/15 - 1 1/15 : 1 3/5 + 2/5) * 2 1/7 - 1 1/7 = 4 6/7
1) 1 1/15 : 1 3/5 = 16/15 : 8/5 = 16/15 * 5/8 = 2/3
2) 3 1/15 - 2/3 = 3 1/15 - 10/15 = 2 16/15 - 10/15 = 2 6/15 = 2 2/5
3) 2 2/5 + 2/5 = 2 4/5
4) 2 4/5 * 2 1/7 = 14/5 * 15/7 = 6
5) 6 - 1 1/7 = 5 7/7 - 1 1/7 = 4 6/7