3/4 : 2/3, 1/3 : (3/4+2/3), (1/3+1/2):(3/7-2/5)
8 12/15+ 5 8/10, 4/15+4/8+4/7+31/56, 1/9+3/16+3/9-2/9
3/8 :7/16, 4/31:7/8

3/4+2/3=1 5/12

3/5-1/3=4/15

3/4-2/3=1/12

3/4+2/14=1/2

1/4-1/6=1/12

3/5+1/3=14/15

4/5+3/4=1 11/20

7/10-1/4= 9/20