Question

(2y/x-x/2y):(2y+x) при x=1/9, y=1/2

Answer 1

$( \frac{2y}{x} - \frac{x}{2y} ):(2y+x)= \frac{4y^2-x^2}{2xy} * \frac{1}{2y+x} = \frac{(2y+x)(2y-x)}{2xy} * \frac{1}{2y+x} =$

$= \frac{2y-x}{2xy} = \frac{2* \frac{1}{2}- \frac{1}{9} }{2* \frac{1}{9} * \frac{1}{2} }= \frac{1- \frac{1}{9} }{ \frac{1}{9} } = \frac{8}{9} : \frac{1}{9} = \frac{8}{9}* 9 =8$