№854.
а) 1/27 + 5/9 + 1/3 = 1/27 + 15/27 + 9/27 = 25/27
б) 2/9 + 5/6 + 1/18 = 4/18 + 15/18 + 1/18 = 20/18 = 10/9 = 1 целая и 1/9
г) 3/8 + 5/12 + 1/24 = 9/24 + 10/24 + 1/24 = 20/24 = 5/6 (сократила на 4)
д) 1/4 + 3/8 + 5/16 = 4/16 + 6/16 + 5/16 = 15/16