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问题: (x根号x+x根号y)/(xy-y^2)-(x+根号xy +y)/(x根号x+y根号y)

(x根号x+x根号y)/(xy-y^2)-(x+根号xy +y)/(x根号x+y根号y)
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解答:

(x√x+x√y)/(xy-y^2)-[x+√(xy)+y]/(x√x-y√y)???
,,,,,,,,,,,,,,,,,,,,,立方差公式a^3-b^3=(a-b)(a^2+ab+b^)
=x(√x+√y)/[y(x-y)]-[x+√(xy)+y]/{(√x-√y)[x+√(xy)+y]}

=x/[y(√x-√y)]-1/(√x-√y)

=(x-y)/[y(√x-√y)] 平方差:a^2-b^2=(a-b)(a+b)

=(√x+√y)/y.