Question

ДАЮ 100 БАЛЛОВ
БАЛЛОВ БАЛЛОВ БАЛЛОВ ​

Answer 1

Ответ:

$1)\ \ \dfrac{y+c}{c}\cdot \Big(\dfrac{c}{y}+\dfrac{c}{y+c}\Big)=\dfrac{y+c}{c}\cdot \dfrac{cy+c^2+cy}{y(y+c)}=\dfrac{c^2+2cy}{c\, y}=\\\\\\=\dfrac{c\, (c+2y)}{c\, y}=\dfrac{c+2y}{y}$

$2)\ \ \Big(\dfrac{c-d}{c^2+cd}-\dfrac{c}{d^2+cd}\Big):\Big(\dfrac{d^2}{c^3-cd^2}+\dfrac{1}{c+d}\Big)=\\\\\\=\Big(\dfrac{c-d}{c(c+d)}-\dfrac{c}{d(c+d)}\Big):\Big(\dfrac{d^2}{c(c-d)(c+d)}+\dfrac{1}{c+d}\Big)=\\\\\\=\dfrac{cd-d^2-c^2}{c\, d(c+d)}:\dfrac{d^2+c^2-cd}{c(c-d)(c+d)}=\\\\\\=\dfrac{cd-d^2-c^2}{c\, d(c+d)}\cdot \dfrac{c(c-d)(c+d)}{-(cd-d^2-c^2)}=-\dfrac{c-d}{d}=\dfrac{d-c}{d}$