в) 6 3/16 - (2 3/8 + 3 5/12)

6 3/16 - (2 9/24 + 3 10/24) = 6 3/16 - 5 19/24 = 6 9/48 - 5 38/48 = 5 57/48 - 5 38/48 = 19/48