вычислите 2/7 + 3/8, 5/6- 4/9, 3 1/8 + 2 5/6, 5 11/12 - 3 7/18

2/7 + 3/8 = 16/56 + 21/56 = 37/56,5/6 - 4/9 = 15/18 - 8/18 = 7/18,3 1/8 + 2 5/6 = 3 3/24 + 2 20/24 = 5 23/24,5 11/12 - 3 7/18 = 5 33/36 - 3 14/36 = 2 19/36