25/30- 20/60+15/30 9/36+36/72-1/9
25/30-20/60+15/30=5/6-2/6+3/6=1.
25/30- 20/60+15/30=50/60-20/60+30/60=30/60+30/60=60/60=1 9/36+36/72-1/9=18/72+36/72-8/72=54/72-8/72=46/72=23/36