3. Решить уравнения: a) $\frac{y}{0.9} = \frac{9}{2.7}$ б) $1\frac{2}{3} : x = \frac{10}{27}$

a) $\frac{y}{0.9} = \frac{9}{2.7}$ $y = \frac{9 \cdot 0.9}{2.7} = \frac{8.1}{2.7} = 3$ б) $1\frac{2}{3} : x = \frac{10}{27}$ $\frac{5}{3} : x = \frac{10}{27}$ $x = \frac{5}{3} : \frac{10}{27} = \frac{5}{3} \cdot \frac{27}{10} = \frac{5 \cdot 27}{3 \cdot 10} = \frac{135}{30} = \frac{9}{2} = 4.5$ Ответ: a) $y = 3$, б) $x = 4.5$