10:(2 12/17+1 5/17)-(3 4/5+1 3/5):6

1) 2 12/17 + 1 6/17 = 3 17/17 =42) 3 4/5 + 1 3/5 = 4 7/5= 5 2/53) 10 : 4 = 10/4 = 5/2 = 2 1/24) 5 2/5 : 6 = 9/105) 2 1/2 - 9/10 = 1 3/5