35. 5(x−y) 15(y-x)

$$\frac{5(x-y)}{15(y-x)} = \frac{5(x-y)}{-15(x-y)} = \frac{5(x-y)}{-3 \cdot 5(x-y)} = -\frac{1}{3}$$ Ответ: $$\frac{-1}{3}$$