3. Реши 34 + ☐ = 169 126 + ☐ = 248 ☐ - 286 = 345 ☐ + 476 = 120

Решим уравнения:

1. 34 + x = 169
   x = 169 - 34
   x = 135
2. 126 + x = 248
   x = 248 - 126
   x = 122
3. x - 286 = 345
   x = 345 + 286
   x = 631
4. x + 476 = 120
   x = 120 - 476
   x = -356

Ответ: 135; 122; 631; -356