6) 6 Реши уравнения: 2) (58:00)務-榜

а) Решим уравнение: \((5\frac{6}{7}+x) \cdot \frac{7}{13} = \frac{7}{15}\cdot \frac{75}{7}\)

\((5\frac{6}{7}+x) \cdot \frac{7}{13} = \frac{7}{15}\cdot \frac{75}{7}\) \((5\frac{6}{7}+x) \cdot \frac{7}{13} = \frac{7 \cdot 75}{15 \cdot 7}\) \((5\frac{6}{7}+x) \cdot \frac{7}{13} = \frac{75}{15}\) \((5\frac{6}{7}+x) \cdot \frac{7}{13} = 5\) \(5\frac{6}{7}+x = 5 : \frac{7}{13}\) \(5\frac{6}{7}+x = 5 \cdot \frac{13}{7}\) \(5\frac{6}{7}+x = \frac{65}{7}\) \(5\frac{6}{7}+x = 9\frac{2}{7}\) \(x = 9\frac{2}{7} - 5\frac{6}{7}\) \(x = 8\frac{9}{7} - 5\frac{6}{7}\) \(x = 3\frac{3}{7}\)

б) Решим уравнение: \((y - 3\frac{1}{2}) + 69 = 87\)

\((y - 3\frac{1}{2}) + 69 = 87\) \(y - 3\frac{1}{2} = 87 - 69\) \(y - 3\frac{1}{2} = 18\) \(y = 18 + 3\frac{1}{2}\) \(y = 21\frac{1}{2}\)