Даю 30 баллов!!!
( x-y/ x^2 +yx -x/ y ^2 +xy ) : ( 1/ x+y + y^2 /x^3 - xy^2) +x/y =1

1)(x-y)/[x(x+y)]-x/[y(x+y)]=(xy-y²-x²)/[xy(x+y)]2)1/(x+y)+y²/[x(x-y)(x+y)]=(x²-xy+y²)/[x(x-y)(x+y)]3)(xy-y²-x²)/[xy(x+y)] *x(x-y)(x+y)/(x²-xy+y²)=-(x-y)/y=(y-x)/y4)(y-x)/y+x/y=(y-x+x)/y=y/y=1