3/4-1/7= 21/28 - 4/28=17/28
7/10 - 4/15 =21/30 - 8/30 = 13/30
3/14 - 1/5=15/70 - 14/70= 1/70
2 i 3/5 - 7/10= 2 i 6/10- 7/10= 1 i 16/10-7/10=9/10
2 i 3/8 - 1 i 5/6 = 2 i 9/24 - 1 i 20/24= 1 i 33/24 - 1 i 20/24 =13/24
3 i 1/6 - 2 i 3/4= 3 i 2/12 - 2 i 9/12= 2 i 14/12 - 2 i 9/12=5/12
