3/4-1/2 5/9-5/12 19/21-11/15 11/21-2/35

Question

3/4-1/2 5/9-5/12 19/21-11/15 11/21-2/35

Answer 1

3/4-1/2=3/4-2/4=1/4=0.25
5/9-5/12=60/108-45/108=15/108=5/36
19/21-11/15=285/315-231/315=54/315=18/105=6/35
11/21-2/35=385/735-42/735=343/735=7/105

Answer 2

3/4-1/2=3/4-2/4=1/4=0.25
5/9-5/12=20/36-15/36=5/36
19/21-11/15=190/210-154/210=36/210=12/70=6/35
11/21-2/35=110/210-12/210=98/210=49/105