Question

Сократите дробь. Фото вложено.

Answer 1

$\frac{ x^{2} +zx-zy+y^2-2xy}{xy-y^2+zx+z^2}= \frac{ (x^{2} +y^2-2xy)+(zx-zy)}{(xy+zx)+(z^2-y^2)}= \\ \\ = \frac{ (x-y)^2+z(x-y)}{x(y+z)+(z-y)(z+y)}= \frac{ (x-y)\cdot (x-y+z)}{(y+z)\cdot (x+z-y)}= \frac{x-y}{y+z}$