1/2-5/12=? 3/4-1/6=? 9/35-2/28=?
1/2 - 5/12 = 6/12 - 5/12 = 1/12 3/4 - 1/6 = 9/12 - 2/12 = 7/12 9/35 - 2/28 = 36/140 - 10/140 = 26/140 = 13/70