Вариант 2. Решите уравнение: a) 8/21 : x = 2/3

a) \(\frac{8}{21} : x = \frac{2}{3}\) \(\frac{8}{21} = \frac{2}{3} x\) \(x = \frac{8}{21} : \frac{2}{3}\) \(x = \frac{8}{21} \cdot \frac{3}{2}\) \(x = \frac{8 \cdot 3}{21 \cdot 2}\) \(x = \frac{24}{42}\) \(x = \frac{4}{7}\)