Условие:
6 + ☐ = 11
8 + ☐ = 12
☐ − 7 = 6
☐ − 8 = 9
14 − ☐ = 5
11 − ☐ = 3

6 + 5 = 11
8 + 4 = 12
13 − 7 = 6
17 − 8 = 9
14 − 9 = 5
11 − 8 = 3

Условие:6 + ☐ = 118 + ☐ = 12☐ − 7 = 6☐ − 8 = 914 − ☐ = 511 − ☐ = 3