3 5/7-1 11/21+2 5/14
3 5/7-1 11/21+2 5/14 = 4 23/423 5/7 + 2 5/14 = 3 10/14 + 2 5/14 = 5 15/14 = 6 1/14 6 1/14 - 1 11/21 = 6 6/84 - 1 44/84 = 5 90/84 - 1 44/84 = 4 46/84 = 4 23/42