а) 1 1/6 + 4 14/15 = 1 10/60 + 4 56/60 = 5 66/60 = 6 6/60 = 6 1/10 = 6,1

b) 4 7/18 - 0,7 = 4 7/18 - 7/10 = 4  70/180 - 126/180 = 3 250/180 - 126/180 = 3 124/180 = 3 31/45

c) 6 1/3 + 2 1/15 - 4 5/9 = 6 15/45 + 2 3/45 - 4 25/45 = 8 18/45 - 4 25/45 = 7 63/45 - 4 25/45 = 3 38/45