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

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