Question

Fatore: x+y/x-y . y/(x+y)² : 1/x+y

Answer 1

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