Question

СРОЧНО!!! НУЖНО СЕЙЧАС!!!

Answer 1

Ответ:

а)

$\frac{5 {y}^{2} }{1 - {y}^{2} } \div (1 - \frac{1}{1 - y} ) = \frac{5 {y}^{2} }{1 - {y}^{2} } \div \frac{1 - y - 1}{1 - y} = \\ = \frac{5 {y}^{2} }{1 - {y}^{2} } \times \frac{1 - y}{( - y)} = - \frac{5 {y}^{2} }{(1 - y)(1 + y)} \times \frac{1 - y}{y} = \\ = - \frac{5y}{1 + y}$

б)

$( \frac{x}{xy - {y}^{2} } - \frac{y}{ {x}^{2} - xy } ) \div \frac{ {x}^{2} - {y}^{2} }{8xy} = \\ = ( \frac{x}{y(x - y)} - \frac{y}{ x (x - y)} ) \times \frac{8xy}{ {x}^{2} - {y}^{2} } = \\ = \frac{ {x}^{2} - {y}^{2} }{xy(x - y)} \times \frac{8xy}{ {x}^{2} - {y}^{2} } = \frac{8}{x - y}$