Решение: Решим уравнения.
1. \(x : 3 = 15\)
\(x = 15 \times 3\)
\(x = 45\)
Проверка: \(45 : 3 = 15\), \(15 = 15\)
2. \(x - 46 = 19\)
\(x = 19 + 46\)
\(x = 65\)
Проверка: \(65 - 46 = 19\), \(19 = 19\)
3. \(90 : x = 30\)
\(x = 90 : 30\)
\(x = 3\)
Проверка: \(90 : 3 = 30\), \(30 = 30\)
4. \(x : 1 = 9\)
\(x = 9 \times 1\)
\(x = 9\)
Проверка: \(9 : 1 = 9\), \(9 = 9\)