1)2 2/5 - ( 1/4+7/10)=2 2/5-(5/20+14/20)=2 2/5+19/20=2 8/20+19/20=2 27/20=3 7/20
2)9 - (1 5/8+3/20)=9-(1 25/40+6/40)=9-1 31/40=8-31/40=7 9/40
3)3 -( 1/6+2/3)=3-(1/6+4/6)=3-5/6=2 1/6
4)4 5/6-(2 3/8+7/12)=4 5/6- (2 9/24+14/24)=4 20/24-2 23/24=2-3/24=2-1/8=1 7/8
5)7 - (2 3/4 + 7/12)=7-(2 9/12+7/12)=7-2 16/12=7-2 4/3=7-3 1/3=4-1/3=3 2/3
6)6 1/4-(3 2/5+3/8)=6 1/4-(3 16/40+15/40)=6 10/40+3 31/40=9 41/40=10 1/40