13/18+7/12,5/6-3/8-1/12,5/7-3/5
13/18 + 7/12 = 26/36 + 21/36 = 47/36 = 1 11/36 5/6 - 3/8 - 1/12 = 20/24 - 9/24 - 2/24 = 9/24 = 3/8 5/7 - 3/5 = 25/35 - 21/35 = 4/35