[-xy/(x-y)^2]^2*·[(y^2-xy)/x]^3
=[xy/(x-y)^2]^2*·[(y^2-xy)/x]^3
=[xy/(x-y)^2]^2*·[y(y-x)/x]^3
=x^2y^2*y^3(y-x)/x^3
=y^5(y-x)/x
(a-b)/(a^2+ab)*·(a^2b^2-a^4)/(ab-a^2)
=(a-b)/[a(a+b)]*·a^2(b^2-a^2)/[a(b-a)]
=-(b^2-a^2)/(a+b)
=(a^2-b^2)/(a+b)
=a-b
太乱了
[-xy/(x-y)^2]^2*·[(y^2-xy)/x]^3
=[xy/(x-y)^2]^2*·[(y^2-xy)/x]^3
=[xy/(x-y)^2]^2*·[y(y-x)/x]^3
=x^2y^2*y^3(y-x)/x^3
=y^5(y-x)/x
(a-b)/(a^2+ab)*·(a^2b^2-a^4)/(ab-a^2)
=(a-b)/[a(a+b)]*·a^2(b^2-a^2)/[a(b-a)]
=-(b^2-a^2)/(a+b)
=(a^2-b^2)/(a+b)
=a-b
太乱了