А) 7/16 + 1/4 = (7+4)/16 = 11/17
б) 25/36 - 2/9 = (25-8)36 = 17/36
в) 7/12 - 5/24 = (14-5)/24 = 9/24 = 3/8
г) 5/7 - 11/21 = (15-11)/21 = 4/21
д) 1/6 + 5/18 = (3+5)/18 = 8/18 = 4/9
е) 19/45 + 4/15 = (19+12)/45 = 31/45
ж) 15/16 - 3/2 = (15-24)/2 = -9/2 = -4 1/2
з) 7/15 + 1/3 = (7+5)/15 = 12/15 = 4/5
и) 11/13 - 20/39 = (33-20)39 = 13/39 = 1/3
к) 3/50 + 18/25 = (3+36)/50 = 39/50
л) 43/62 - 10/31 = (43-20)/62 = 23/62
м) 29/64 + 3/8 = (29+24)/64 = 53/64