Question

（x的平方-xy分之y+y的平方-xy分之X）乘x-y分之xy

Answer 1

（x的平方-xy分之y+y的平方-xy分之X）乘x-y分之xy
=[y/x(x-y)-x/y(x-y)]*[xy/(x-y)]
=[(y²-x²)/xy(x-y)]*xy/(x-y)
=-(x-y)(x+y)/(x-y)²
=-(x+y)/(x-y)
希望能帮到你O(∩_∩)O

Answer 2

（x的平方-xy分之y+y的平方-xy分之X）乘x-y分之xy
=（y/x^2-xy+x/y^2-xy）*(xy/x-y)
=（y(y^2-xy)+x(x^2-xy))/(x^2-xy)(y^2-xy）*(xy/x-y)
=（y^2(y-x)+x^2(x-y))/xy(x-y)(y-x）*(xy/x-y)
=(x^2-y^2)(x-y)/(y-x)
=y^2-x^2