Объяснение:
1. (x+y)/(x-y)-(x-y)/(x+y)=((x+y)²-(x-y)²)/((x+y)(x-y))=
=(x²+2xy+y²-x²+2xy-y²)/((x+y)(x-y))=4xy/((x+y)(x-y)).
2. (4xy/((x+y)(x-y)))*(x-y)/2y=2x/(x+y).
((x+y/(x-y )- x-y/(x+y))*(x-y)/2y=2х/(х+у)
1) (x+y/(x-y )- x-y/(x+y))=((x+y)²-(х-у)²)/(x²-y² )=2у*2х/(х²-у²)=4ху/(х²-у²)
2)(4ху/(х²-у²))*((x-y)/2y)=2х/(х+у)
