1 - 7/18=18/18 - 7/18=11/18
15 2/7 - 7=15 - 7 +2/7=8 2/7
11 - 5 3/13=11-5-3/13=6 - 3/13=5 13/13 - 3/13=5 10/13
6 3/5 - 3 5/12=6 - 3 +36/60 - 25/60=3+11/60=3 11/60
9 2/5 - 3 7/8=9 16/40 - 3 35/40=8 56/40 - 3 35/40=5 21/40
19 7/12+43 5/12=19+43+7/12+5/12=62+12/12=62+1=63
7 7/15+4 11/12=7 28/60+4 55/60=11 83/60=12 23/60
5 5/9+7 3/5+1 7/18=5 50/90+7 54/90+1 35/90=13 139/90=14 49/90
8 7/8+3 2/5 - 2 3/4=8 35/40+316/40 - 2 30/40=9 25/40=9 5/8