8,25: (3 1/2+4 3/4)+(3/4+5/6): 6 1/3 плес

8,25 : (3 1/2 + 4 3/4) + (3/4 + 5/6) : 6 1/3 = 2,

1) 3 1/2 + 4 3/4 = (3 + 4) + (2/4 + 3/4) = 7 + 5/4 = 8 1/4,
2) 8,25 : 8 1/4 = 8 1/4 : 8 1/4 = 1,
3) 3/4 + 5/6 = 9/12 + 10/12 = 19/12 = 1 7/12,
4) 1 7/12 : 6 1/3 = 19/12 : 19/12 = 1,
5) 1 + 1 = 2