Question

Ничего не получается. Прошу, помогите.

Answer 1

$1)quad frac{4c+3y}{c^2-y^2} - frac{3}{c-y} = frac{4c+3y}{(c-y)(c+y)} - frac{3}{c-y} = frac{4c+3y-3(c+y)}{(c-y)(c+y)} =\\= frac{c}{(c-y)(c+y)} \\2)quad frac{c}{(c-y)(c+y)} + frac{1}{y-c} = frac{c}{(c-y)(c+y)} - frac{1}{c-y} = \\=frac{c-(c+y)}{(c-y)(c+y)} = frac{-y}{(c-y)(c+y)} \\3)quad frac{-y}{(c-y)(c+y)y} - frac{4}{5y+5c} = frac{-y}{(c-y)(c+y)} - frac{4}{5(c+y)} =\\= frac{-5y-4(c-y)}{5(c-y)(c+y)} = frac{-y-4c}{5(c-y)(c+y)} =- frac{y+4c}{5(c^2-y^2)}$