8 1/4÷1 1/10-(3-2 4/5×3/7)=

8 1/4 : 1 1/10 - (3 - 2 4/5 * 3/7) = 5 7/10

1) 2 4/5 * 3/7 = 14/5 * 3/7 = (2*3)/(5*1) = 6/5 = 1 1/5
2) 3 - 1 1/5 = 2 5/5 - 1 1/5 = 1 4/5
3) 8 1/4 : 1 1/10 = 33/4 : 11/10 = 33/4 * 10/11 = (3*5)/(2*1) = 15/2 = 7 1/2
4) 7 1/2 - 1 4/5 = 7 5/10 - 1 8/10 = 6 15/10 - 1 8/10 = 5 7/10