А) 2 3/4 - 1 5/6 = 2 9/12 - 1 10/12 = 1 21/12 - 1 10/12 = 11/12;
б) 4 2/5 + 3 5/6 = 4 12/30 + 3 25/30 = 7 37/30 = 8 7/30;
в) 7 5/12 - (1 5/8 + 2 1/24) = 3 3/4
1) 1 5/8 + 2 1/24 = 1 15/24 + 2 1/24 = 3 16/24 = 3 2/3
2) 7 5/12 - 3 2/3 = 7 5/12 - 3 8/12 = 6 17/12 - 3 8/12 = 3 9/12 = 3 3/4