е) \frac{2}{7}x + \frac{3}{7}x = 2\frac{7}{14};

е) \(\frac{2}{7}x + \frac{3}{7}x = 2\frac{7}{14}\)

1. \(\frac{5}{7}x = 2\frac{1}{2}\)
2. \(\frac{5}{7}x = \frac{5}{2}\)
3. \(x = \frac{5}{2} : \frac{5}{7}\)
4. \(x = \frac{5}{2} \cdot \frac{7}{5}\)
5. \(x = \frac{5 \cdot 7}{2 \cdot 5}\)
6. \(x = \frac{7}{2}\)
7. \(x = 3\frac{1}{2}\)

Ответ: 3,5