23) 23 : (6 5/17 + 1 12/17) - (4 2/5 - 2 3/5) : 5;

23 : (6 + 5/17 + 1 + 12/17) - (4 - 2 + 2/5 - 3/5) : 5 = 23 : (7 + 17/17) - (2 - 1/5) : 5 = 23 : 8 - 1,8 : 5 = 2,875 - 0,36 = 2,515