Ответ:

2 + 6 = 8;

2 + 7 = 9;

8 − 4 = 4;

9 − 5 = 4;

7 − 6 + 8 = 1 + 8 = 9;

9 − 7 + 5 = 2 + 5 = 7;

10 − 0 = 10;

18 + 0 = 18.

Ответ: 8, 9, 4, 4, 9, 7, 10, 18.