14/18 + 10/12 - 2 целых 14/24 =
= 7/9 + 5/6 - 2 целых 7/12 =
= 28/36 + 30/36 - 2 целых 21/36 =
= 58/36 - 93/36 = - (93/36 - 58/36) = - 35/36
Ответ: - 35/36.
Пояснения:
14/18 = 7/9 = 28/36
10/12 = 5/6 = 30/36
14/24 = 7/12 = 21/36
2 целых 21/36 = (2*36+21)/36 = 93/36