л) (\frac{5}{8}x - \frac{1}{5}) \cdot 3\frac{3}{4} = \frac{3}{4};

л) \((\frac{5}{8}x - \frac{1}{5}) \cdot 3\frac{3}{4} = \frac{3}{4}\)

1. \((\frac{5}{8}x - \frac{1}{5}) \cdot \frac{15}{4} = \frac{3}{4}\)
2. \((\frac{5}{8}x - \frac{1}{5}) = \frac{3}{4} : \frac{15}{4}\)
3. \((\frac{5}{8}x - \frac{1}{5}) = \frac{3}{4} \cdot \frac{4}{15}\)
4. \((\frac{5}{8}x - \frac{1}{5}) = \frac{1}{5}\)
5. \(\frac{5}{8}x = \frac{1}{5} + \frac{1}{5}\)
6. \(\frac{5}{8}x = \frac{2}{5}\)
7. \(x = \frac{2}{5} : \frac{5}{8}\)
8. \(x = \frac{2}{5} \cdot \frac{8}{5}\)
9. \(x = \frac{16}{25}\)

Ответ: 16/25