1/5-1/6= 3/4-1/3= 7/9-2/11 3/4-4/9= 7/5-6/12= 11/12-11/18=

1/5-1/6= =6/30-5/30=1/30

3/4-1/3= 9/12-4/12=5/12

7/9-2/11=77/99-18/99=59/99

3/4-4/9= 27/36-16/36=11/36

7/5-6/12=84/60-30/60=54/60=9/10

11/12-11/18=33/36-22/36=11/36