Question

Сократите дробь:y^2-z^2/2y-2z;a^2-1/a^2-2a+1

Answer 1

$frac{y^2-z^2}{2y-2z}= frac{(y-z)(y+z)}{2(y-z)}= frac{y+z}{2} \ frac{a^2-1}{a^2-2a+1}= frac{(a-1)(a+1)}{(a-1)^2}= frac{a+1}{a-1}$