А) 3/5 - 7/15 = 2/15 б) 1/6 + 1/4 = 10/24
2/15 : 2/3 = 1/5 10/24 + 3/8 = 19/24
1/5 * 7/8 = 7/40 19/24 : 9 1/2 = 1/12
7/40 * 5 5/7 = 1 1/12 * 12 = 1
в) 7/9 - 1/3 = 4/9 г) 1/5 + 1/3 = 8/15
4/9 + 1/6 = 11/18 8/15 - 3/10 = 7/30
11/18 : 5 1/2 = 1/9 7/30 : 2 1/3 = 1/10
1/9 * 4 1/2 = 1/2 1/10 * 10 = 1