8) 1 a²b² + a²b+ab² + 5 3 5 4 a²b² =

Приведем подобные члены многочлена:

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

Ответ: $$a^2b^2 + \frac{2}{3}a^2b + \frac{4}{5}ab^2$$