10) a/b = x/y

10) $$ \frac{a}{b} = \frac{x}{y} $$

1. $$ \frac{b}{a} = \frac{y}{x} $$
2. $$ \frac{a}{x} = \frac{b}{y} $$
3. $$ \frac{x}{a} = \frac{y}{b} $$

Ответ: $$ \frac{b}{a} = \frac{y}{x}; \frac{a}{x} = \frac{b}{y}; \frac{x}{a} = \frac{y}{b} $$