2 2/5 - 1/4 - 7/10 = 12/5 - 1/4 - 7/10 = 48/20-5/20 -14/20= 29/20 = 1 9/20
9 - 1 5/8 - 3/20 = 360/40 - 65/40 - 6/40 = 289/40 = 7 9/40
3 - 1/6 - 2/3 = 18/6 - 1/6 - 4/6 = 13/6 = 2 1/6
4 5/6*(2 3/8 + 7/12) = 29/6*19/8 + 29/6*7/12 = 551/48 + 203/72 = 1653/144 + 406/144 = 2059/144 = 14 43/144
7-2 3/4 - 7/12 = 7 - 11/4 - 7/12 = 84/12 - 33/12 - 7/12 = 44/12 = 3 8/12 = 3 2/3
6 1/4 - 3 2/5 - 3/8 = 25/4 - 17/5 - 3/8 = 250/40 - 136/40 - 15/40 = 99/40 = 2 19/40