А) 3 + 8 5/12 = (3 + 8) + 5/12 = 11 + 5/12 = 11 5/12
б) 10 6/7 - 3 = (10 - 3) + 6/7 = 7 + 6/7 = 7 6/7
в) 4 2/13 + 5 7/13 = (4 + 5) + (2/13 + 7/13) = 9 + 9/13 = 9 9/13
г) 8 7/12 - 4 2/12 = (8 - 4) + (7/12 - 2/12) = 4 + 5/12 = 4 5/12
д) 4 8/11 + 5 7/11 = (4 + 5) + (8/11 + 7/11) = 9 + 15/11 = 9 + 1 4/11 = 10 4/11
е) 7 5/9 - 2 8/9 = (7 - 2) + (5/9 - 8/9) = 5 + (- 3/9) = 5 - 3/9 = 4 6/9 = 4 2/3
ж) 7 - 3/8 = 6 + (8/8 - 3/8) = 6 + 5/8 = 6 5/8
з) 10 - 3 7/15 = (10 - 3) - 7/15 = 7 - 7/15 = 6 + (15/15 - 7/15) = 6 + 8/15 = 6 8/15