5/6-3/4=10/12-9/12=1/12
9/14+8/21=27/42+16/42=43/42=1 1/42
7/9+5/12-3/4=28/36+15/36-27/36=43/36-27/36=16/36=4/9
13/18+7/12=26/36+21/36=47/36=1 11/36
5/7-3/5=25/35-21/35=4/35
5/6-3/8-1/12=20/24-9/24-2/24=9/24=3/8
7/8-5/6=21/24-20/24=1/24
3/16+7/24=9/48+14/48=23/48
19/20-5/12+9/5=57/60-25/60+108/60=140/60=2 20/60=2 1/3
3/4-1/6=9/12-2/12=7/12
11/12+9/10=55/60+54/60=109/60=1 49/60
5/6+3/8-1/3 =20/24+9/24-8/24=21/24