№ 2
а) 2 3/5 + 1 4/5 = 3 7/5 = 4 2/5
б) 4 2/7 + 3 5/7 = 7 7/7 = 8
в) 7 - 4 8/9 = 6 9/9 - 4 8/9 = 2 1/9
г) 5 1/6 - 1 2/6 = 4 7/6 - 1 2/6 = 2 5/6
д) (3 1/15 - 2 7/15) + (6 - 3 2/15) = (2 16/15 - 2 7/15) + (5 15/15 - 3 2/15) = 9/15 + 2 13/15 = 2 22/15 = 3 7/15
е) 1 7/18 + 3 1/4 + 5 11/18 + 1 3/4 = 1 7/18 + 5 11/18 + 3 1/4 + 1 3/4 = 6 18/18 + 4 4/4 = 7 + 5 = 12