1) 2 2/5 - (1/4 + 7/10) = 2 2/5 - (5+14)/20 = 2 2/5 - 19/20 = 12/5 - 19/20 = (48-19)/20 = 29/20 = 1 9/20
2) 9 - (1 5/8 + 3/20) = 9 - (13/8 + 3/20) = 9 - (65+6)/40 = 9 - 71/40 = 9 - 1 31/40 = 7 9/40
3) 3 - (1/6 + 2/3) = 3 - (1+4)/6 = 3 - 5/6 = 2 1/6
4) 4 5/6 - (2 3/8 + 7/12) = 29/6 - (19/8 + 7/12) = 29/6 - (57+14)/24 = 29/6 - 71/24 = (156-71)/24 = 85/24 = 3 13/24
5) 7 - (2 3/4 + 7/12) = 7 - (11/4 + 7/12) = 7 - (33+7)/12 = 7 - 40/12 = 7 - 3 4/12 = 3 8/12 = 3 2/3
6) 6 1/4 - (3 2/5 + 3/8) = 25/4 - (17/5 + 3/8) = 25/4 - (136+15)/40 = 25/4 - 151/40 = (250-151)/40 = 99/40 = 2 19/40