А) 5/6 - 2/3 = 5/6 - 4/6 = 1/6
б) 5/6 - 7/12 = 10/12 - 7/12 = 3/12 = 1/4
в) 11/15 - 2/3 = 11/15 - 10/15 = 1/15
г) 40/60 - 9/15 = 2/3 - 9/15 = 10/15 - 9/15 = 1/15
д) 2/3 - 1/8 = 16/24 - 3/24 = 13/24
е) 17/42 - 6/21 = 17/42 - 12/42 = 5/42
ж) 2/8 - 4/24 = 6/24 - 4/24 = 2/24 = 1/12
з) 23/45 - 4/15 = 23/45 - 12/45 = 11/45