1. x + 10 = 7/8

x = 7/8 - 10

2. x = 7/8 - 10 = (7 - 80)/8 = -73/8

3. -3 1/2 = -7/2

4. -7/2 + 7 3/4

5. -7/2 = -28/4

6. -28/4 + 7/4 = (-28 + 7) / 4 = -21/4

7.x + 10 = 7/8 - 3 1/2 = -73/8 + (-21/4) = -73/8 - 21/4 = -73/8 - 42/8 = -115/8

Таким образом, ответ равен -115/8.