4. Решите уравнение: a) \(3\frac{4}{15} + y = 7\frac{11}{15}\); б) \(5\frac{4}{13} - x = 4\frac{5}{13}\).

Решим уравнения:

1. a) \(3\frac{4}{15} + y = 7\frac{11}{15}\)
   \(y = 7\frac{11}{15} - 3\frac{4}{15}\)
   \(y = (7 - 3) + (\frac{11}{15} - \frac{4}{15})\)
   \(y = 4 + \frac{7}{15}\)
   \(y = 4\frac{7}{15}\)
2. б) \(5\frac{4}{13} - x = 4\frac{5}{13}\)
   \(x = 5\frac{4}{13} - 4\frac{5}{13}\)
   \(x = 4\frac{17}{13} - 4\frac{5}{13}\)
   \(x = (4 - 4) + (\frac{17}{13} - \frac{5}{13})\)
   \(x = 0 + \frac{12}{13}\)
   \(x = \frac{12}{13}\)

Ответ: а) \(y = 4\frac{7}{15}\); б) \(x = \frac{12}{13}\).