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己知x-y=6,√x²-xy+√xy-y²=9,则√x²-xy-√xy-y²的值是多少

题目详情
己知x-y=6,√x²-xy+√xy-y²=9,则√x²-xy-√xy-y²的值是多少
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答案和解析
根号x^2-xy+根号xy-y^2 =s;根号x^2-xy-根号xy-y^2 =t;根号x^2-xy+根号xy-y^2=9[根号x^2-xy+根号xy-y^2]^2 =81=x^2-y^2+2根号[(x^2-xy)(xy-y^2)]x^2-y^2+2根号[xy(x-y)^2] =816(x+y)+2根号(36xy) =816(x+y)+12根号(xy...