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) $$x = 4.5$$