1/2-5/12=?
3/4-1/6=?
9/35-2/28=?

1/2 - 5/12 = 6/12 - 5/12 = 1/123/4 - 1/6 = 9/12 - 2/12 = 7/129/35 - 2/28 = 36/140 - 10/140 = 26/140 = 13/70