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若x+y-5xy=0,求(2x-3xy+2y)/(x+2xy+y)的值

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若x+y-5xy=0,求(2x-3xy+2y)/(x+2xy+y)的值
若x+y-5xy=0,求(2x-3xy+2y)/(x+2xy+y)的值
x+y=5xy
(2x-3xy+2y)/(x+2xy+y)
=[2(x+y)-3xy]/[(x+y)+2xy]
=(2×5xy-3xy)/(5xy+2xy)
=7xy/7xy
=1
再问: 若x+1/x=3,求(x^4+x^2+1)/x^2的值.
再答: (x+1/x)²=x²+2+1/(x²)=9 x²+1/(x²)=9-2=7 你可以把 (x^4+x²+1)/x²=x²[x²+1+1/(x²)]/x² 约掉x² 等于x²+1+1/(x²)=7+1=8 希望采纳,不懂请追问!谢谢!