3 1/8 : ((3 13/24 - 4 5/12) * 4/7 + (2 7/12 - 3 1/18) * 1 10/17) = - 2 1/2
1) 3 13/24 - 4 5/12 = 3 13/24 - 4 10/24 = - (4 10/24 - 3 13/24) = - (3 34/24 - 3 13/24) = - 21/24 = - 7/8
2) - 7/8 * 4/7 = - 4/8 = - 1/2
3) 2 7/12 - 3 1/18 = 2 21/36 - 3 2/36 = - (3 2/36 - 2 21/36) = - (2 38/36 - 2 21/36) = - 17/36
4) - 17/36 * 1 10/17 = - 17/36 * 27/17 = - 27/36 = - 3/4
5) - 1/2 + (-3/4) = - 2/4 - 3/4 = - 5/4
6) 3 1/8 : (-5/4) = 25/8 * (-4/5) = -(5*1)/(2*1) = - 5/2 = - 2 целых 1/2