8) 1 5 a²b² + 2 5 a²b+ 3 5 ab² +4/5 a²b² =

8) Приведем подобные слагаемые:

$$\frac{1}{5}a^2b^2 + \frac{2}{5}a^2b + \frac{3}{5}ab^2 + \frac{4}{5}a^2b^2 = (\frac{1}{5} + \frac{4}{5})a^2b^2 + \frac{2}{5}a^2b + \frac{3}{5}ab^2 = \frac{5}{5}a^2b^2 + \frac{2}{5}a^2b + \frac{3}{5}ab^2 = a^2b^2 + \frac{2}{5}a^2b + \frac{3}{5}ab^2$$

Ответ: $$a^2b^2 + \frac{2}{5}a^2b + \frac{3}{5}ab^2$$