1) -(4 - 3/7) = -(3 целых 7/7 - 3/7) = - 3 целых 4/7
2) -11/12-( + 8/9 = -(11/12 - 8/9) = -(33/36 - 32/36) = -1/36
3) -(5 целых 3/28 - 4 целые 5/12) = -(1 целая 9/84 - 35/84) = -(93/84 - 35/84) = -58/84 = - 29/42
4) -3 целых 7/12 + (-2 целых 5/8) = -(3 целых 14/24 + 2 целые 15/24) = -5 целых 29/24 = -6 целых 5/24