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xiaxiao 发表于 2008-2-14 17:40

求x的取值范围

x/y=x-y,求x的取值范围。<br>

fanyun 发表于 2008-2-14 17:40

x≠0吧<br>

IMath 发表于 2008-2-14 17:40

x\y=x-y&nbsp; &nbsp;x≠0 <br />x=xy-y2<br />-x+xy=y2<br />x(y-1)=y2<br />x=y2\y-1<br />y ≠1<br /><br>

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