数学问题(1)
已知1/x-1/y=2,则代数式xy/x-y的值是
原式可展开为(y-x)/xy=2,则y-x=2xy,x-y=-2xy,所以xy/(x-y)=xy/-2xy=-½
y/xy-x/xy=2
(y-x)/xy=2
y-x=2xy
x-y=-2xy
xy/(x-y)=-1/2
1/x-1/y=(y-x)/xy=2
xy/x-y=-1/2
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已知1/x-1/y=2,则代数式xy/x-y的值是
原式可展开为(y-x)/xy=2,则y-x=2xy,x-y=-2xy,所以xy/(x-y)=xy/-2xy=-½
y/xy-x/xy=2
(y-x)/xy=2
y-x=2xy
x-y=-2xy
xy/(x-y)=-1/2
1/x-1/y=(y-x)/xy=2
xy/x-y=-1/2