Упростите выражение (x-y/x^2-xy - 1/x^2-y^2 : x+y/(x+y)^2) : y^2/(x+y)^2

((x^2+y^2/2xy)-1)):(1/y-1/x)^2 = ((x^2+y^2 - 2xy) / 2xy) : ((x-y)/xy)^2 =((x-y)^2/2xy)*((xy)^2/(x-y)^2)=xy/2;При x=√3-2, y=√3+2. xy/2= (√3-2)(√3+2)/2 = (3-4)/2 = -1/2.Ответ: -0,5