Question

Сократите дробь 5x-7x² - 5y + 7xy/ y² - x²​

Answer 1

$\frac{5x - 7 {x}^{2} - 5y + 7xy }{ {y}^{2} - {x}^{2} } = \\ = \frac{5(x - y) - 7x(x - y)}{(y - x)( y + x)} = \\ = \frac{(5 - 7x)(x - y)}{ -(x - y)(x + y)} = \frac{7x - 5}{x + y}$