2 2/5-(1/4+7/10)=2 8/20-(5/20+14/20)=2 8/20-19/20=1 28/20-19/20=1 9/20
---------------------
9-(1 5/8+3/20)=9-(1 25/40+6/40)=8 40/40-1 31/40=7 9/40
--------------------
3-(1/6+2/3)=3-(1/6+4/6)=2 6/6-5/6=2 1/6
-------------------
4 5/6-(2 3/8+7/12)=4 20/24-(2 9/24+14/24)=4 20/24-2 23/24=
=3 44/24-2 23/24=1 21/24=1 7/8