已知1/x-1/y=3.求分式(2x+3xy-2y)/(x-2xy-y)

来源:百度知道 编辑:UC知道 时间:2024/06/30 17:41:32
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1/x - 1/y=3
y-x/xy=3
3xy=y-x
2x+3xy-2y / x-2xy-y
=-2(y-x)+3xy/-(y-x)-2xy
=-2*3xy+3xy/-3xy-2xy
=-6xy+3xy/-5xy
=-3xy/-5xy
=3/5

解:已知1/x-1/y=3,得x-y=-3xy
(2x+3xy-2y)/(x-2xy-y)=[2(x-y)+3xy]/[(x-y)-2xy]
将x-y=-3xy代入,得
[2*(-3xy)+3xy]/(-3xy-2xy)
=3xy/5xy
=3/5

已知1/x-1/y=3.
SO Y-X=3XY
代入(2X+Y-X-2Y)/(X-Y-2/3Y+2/3X)=(X-Y)/(5X—5Y)/3
=3/5
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