Question

помогите сократить дробь

Answer 1

$frac{x^2-y^2-2yz-z^2}{x^2+xz-y^2-yz}=frac{x^2-(y^2+2yz+z^2)}{(x^2-y^2)+(xz-yz)}=frac{x^2-(y+z)^2}{(x-y)(x+y)+z(x-y)}=\\=frac{(x-y-z)(x+y+z)}{(x-y)(x+y+z)}=frac{x-y-z}{x-y}$