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[(y*y*y-y)/(xy+1)*(xy+1)-(x+y)*(x+y)]/[(x+y)*y/(x+1)]其中x=-11

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/10/01 11:10:03
[(y*y*y-y)/(xy+1)*(xy+1)-(x+y)*(x+y)]/[(x+y)*y/(x+1)]其中x=-11,y=1/12,化简再求值.
原式=[y(y+1)(y-1)/(xy+1+x+y)(xy+1-x-y)]*[(x+1)/u(x+y)]
=[y(y+1)(y-1)/(x+1)(y+1)(x-1)(y-1)]*[(x+1)/y(x+y)]
=[y/(x+1)(x-1)]*[(x+1)/y(x+y)]
=1/(x-1)(x+y)
=1/131