Так, там 3 целых и дробь идет?
3 1/2 - 5/9 = 7/2 - 5/9 = (63-10)/18 = 53/18=2 17/18
б) 5/4 -1/3 = (15 - 4)/12 = 11/12
в) 28/15 - 2/5 = (140 - 30)/75 = 110/75 = 22/15
в) 22/15 = 1 7/15
г) 4/3 - 5/6 = (24 - 15)/18 = 9/18 = 2
д)13/10 - 4/15 = (195 - 40) /150 = 155/150 = 31/30 = 1 1/30
е) 25/8 - 1/6 = (150 - 8)/48 = 142/48 = 71/24=2 23/24