5/9+13/27= 15/27+13/27=28/27=1 1/27
3/8+5/24=9/24+5/24=14/24=7/12
5/12-13/72=30/72-13/72=17/72
3/5-1/7=21/35-5/35=16/35
5/12+1/60=25/60+1/60=26/60=13/30
9/17-19/68=36/68-19/68=17/68=1/4
9/10+4/15=27/30+8/30=35/30=1 5/30= 1 1/6
4/15-11/60=16/60-11/60=5/60=1/12