Question

Помогите решить 2 примера.

Answer 1

$\dfrac{a^2-b^2}{25ab} : \dfrac{(a-b)^2}{30a^2} = \dfrac{(a-b)(a+b)}{25ab} * \dfrac{30a^2}{(a-b)^2}=\\\\ = \dfrac{a+b}{5b}*\dfrac{6a}{a-b} = \dfrac{6a(a+b)}{5b(a-b)} = \dfrac{6a^2+6ab}{5ab-5b^2}$

$\dfrac{(x-5)^2}{48x^2y^2} : \dfrac{25-x}{36x^3y^2} = \dfrac{(x-5)^2}{48x^2y^2} * \dfrac{36x^3y^2}{25-x} = \dfrac{(x-5)^2}{4}*\dfrac{3x}{(5-x)(5+x)} = \\\\= \dfrac{(x-5)^2}{4}*\dfrac{3x}{-(x-5)(5+x)} = \dfrac{-(x-5)}{4}*\dfrac{3x}{5+x} = -\dfrac{3x(x-5)}{4(5+x)} = \\\\=- \dfrac{3x^2-15x}{4(5+x)} = \dfrac{15x-3x^2}{20+4x}$