Question

Помогите прошу! Завтра контрольная :(

Answer 1

$frac{7(y+5)}{(y-5)(y^2+5y+25)}*frac{y^2+5y+25}{(y+5)^2}-frac{2}{y^2-25}=frac{7}{y-5}*frac{1}{y+5}-frac{2}{y^2-25}=frac{7}{y^2-25}-frac{2}{y^2-25}=frac{5}{y^2-25}$

Answer 2

$tt{} cfrac{7y+35}{y^3-125} cdot cfrac{y^2+5y+25}{y^2+10y+25}-cfrac{2}{y^2-25}=\\\=cfrac{7(y+5)}{(y-5)(y^2+5y+25)} cdot cfrac{y^2+5y+25}{(y+5)^2}-cfrac{2}{y^2-25}=\\\=cfrac{7}{y-5} cdot cfrac{1}{y+5}-cfrac{2}{y^2-25}=cfrac{7-2}{y^2-25}=cfrac{5}{y^2-25}$