16. Найдите значение выражения $$\frac{x^3y + xy^3}{2(y-x)^2} + \frac{5(x-y)}{x^2+y^2}$$ при $$x = -3$$ и $$y = \frac{1}{3}$$.
$$\frac{(-3)^3 \cdot \frac{1}{3} + (-3) \cdot (\frac{1}{3})^3}{2(\frac{1}{3} - (-3))^2} + \frac{5(-3 - \frac{1}{3})}{(-3)^2 + (\frac{1}{3})^2} = \frac{-27 \cdot \frac{1}{3} - 3 \cdot \frac{1}{27}}{2(\frac{1}{3} + 3)^2} + \frac{5(-\frac{10}{3})}{9 + \frac{1}{9}} =$$
$$= \frac{-9 - \frac{1}{9}}{2(\frac{10}{3})^2} + \frac{-\frac{50}{3}}{\frac{82}{9}} = \frac{-\frac{82}{9}}{2 \cdot \frac{100}{9}} - \frac{50 \cdot 9}{3 \cdot 82} = \frac{-\frac{82}{9}}{\frac{200}{9}} - \frac{150}{82} = -\frac{82}{200} - \frac{75}{41} = -\frac{41}{100} - \frac{75}{41} = -\frac{41 \cdot 41 + 75 \cdot 100}{4100} = -\frac{1681 + 7500}{4100} = -\frac{9181}{4100}$$.
Ответ: -9181/4100