[-(xy)/(x-y)²]^4*(y²-xy/x)³*x^4/y^10÷(x/xy-y²)^5,y=-1就是（y²-xy）³(xy-y²)^5/(x-y)^8*y^6,就是y³,y=-1

[-(xy)/(x-y)²]^4*(y²-xy/x)³*x^4/y^10÷(x/xy-y²)^5,y=-1就是（y²-xy）³(xy-y²)^5/(x-y)^8*y^6,就是y³,y=-1
[-(xy)/(x-y)²]^4*(y²-xy/x)³*x^4/y^10÷(x/xy-y²)^5,y=-1
就是（y²-xy）³(xy-y²)^5/(x-y)^8*y^6,就是y³,y=-1

[-(xy)/(x-y)²]^4*(y²-xy/x)³*x^4/y^10÷(x/xy-y²)^5,y=-1就是（y²-xy）³(xy-y²)^5/(x-y)^8*y^6,就是y³,y=-1
（-1）³,原式=-1