Выполните умножение:
1) $\frac{2xy - y^2}{9} * \frac{36}{y^4}$;
2) $\frac{a^2 - 7ab}{a^2 + 2ab} * \frac{a^2b + 2ab^2}{a^3 - 7a^2b}$;
3) $\frac{m^2 - 64}{m^3 - 9m^2} * \frac{m^2 - 81}{m^2 + 8m}$;
4) $\frac{2x^2 - 16x + 32}{3x^2 - 6x + 12} * \frac{x^3 + 8}{4x^2 - 64}$.
$\frac{2xy - y^2}{9} * \frac{36}{y^4} = \frac{y(2x - y)}{1} * \frac{4}{y^4} = \frac{4(2x - y)}{y^3}$
$\frac{a^2 - 7ab}{a^2 + 2ab} * \frac{a^2b + 2ab^2}{a^3 - 7a^2b} = \frac{a(a - 7b)}{a(a + 2b)} * \frac{ab(a + 2b)}{a^2(a - 7b)} = \frac{b}{a}$
$\frac{m^2 - 64}{m^3 - 9m^2} * \frac{m^2 - 81}{m^2 + 8m} = \frac{(m - 8)(m + 8)}{m^2(m - 9)} * \frac{(m - 9)(m + 9)}{m(m + 8)} = \frac{m - 8}{m^2} * \frac{m + 9}{m} = \frac{(m - 8)(m + 9)}{m^3}$
$\frac{2x^2 - 16x + 32}{3x^2 - 6x + 12} * \frac{x^3 + 8}{4x^2 - 64} = \frac{2(x^2 - 8x + 16)}{3(x^2 - 2x + 4)} * \frac{(x + 2)(x^2 - 2x + 4)}{4(x^2 - 16)} = \frac{2(x - 4)^2}{3} * \frac{x + 2}{4(x - 4)(x + 4)} = \frac{x - 4}{3} * \frac{x + 2}{2(x + 4)} = \frac{(x - 4)(x + 2)}{6(x + 4)}$
Пожауйста, оцените решение
