3. Реши уравнения: x + 327 = 700; 5x = 45; x : 7 = 12.

1. \(x + 327 = 700\)
   \(x = 700 - 327\)
   \(x = 373\)
2. \(5x = 45\)
   \(x = 45 : 5\)
   \(x = 9\)
3. \(x : 7 = 12\)
   \(x = 12 \cdot 7\)
   \(x = 84\)

Ответ: \(x = 373;\ x = 9;\ x = 84\).