(1/2x-y) -( 1/2x+y) + (4x/4x²-y²) =( 2x+y -(2x-y)+ 4x )/(2x-y)(2x+y)=
= 2(y+2x)/ (2x-y)(2x+y) = 2/(2x-y)
(1/2x-y) -( 1/2x+y) + (4x/4x²-y²) =( 2x+y -(2x-y)+ 4x )/(2x-y)(2x+y)=
= 2(y+2x)/ (2x-y)(2x+y) = 2/(2x-y)