Question

помогите срочно very срочно

Answer 1

Ответ:

$\dfrac{a^2+2ab+10b}{a+2b}\cdot \dfrac{1}{a-2b}-\dfrac{a^2+2ab+4b^2}{a-5}\, :\, \dfrac{a^3-8b^3}{a^2-25}=\\\\\\=\dfrac{a^2+2ab+10b}{(a+2b)(a-2b)}-\dfrac{a^2+2ab+4b^2}{a-5}\cdot \dfrac{(a-5)(a+5)}{(a-2b)(a^2+2ab+4b^2)}=\\\\\\=\dfrac{a^2+2ab+10b}{(a-2b)(a+2b)}-\dfrac{a+5}{a-2b}=\dfrac{a^2+2ab+10b-(a+5)(a+2b)}{(a-2b)(a+2b)}=\\\\\\=\dfrac{a^2+2ab+10b-(a^2+2ab+5a+10b)}{(a-2b)(a+2b)}=-\dfrac{5a}{a^2-4b^2}$