谈歌唱文
幼苗
共回答了55个问题 举报
2xy/(x²-y²)+x/(x+y)=2xy/[(x+y)(x-y)]+x(x-y)/[(x+y)(x-y)]=[2xy+(x²-xy)]/[(x+y)(x-y)]
=[x(x+y)]/[(x+y)(x-y)]=x/(x-y)
[a²/(a-2)-4/(a-2)]*[1/(a²+2a)]=[(a²-4)/(a-2)]/[a(a+2)]=(a+2)/[a(a+2)]=1/a
[1+3/(x-1)]÷[(x+2)/(x²-1)]=[(x+2)/(x-1)][(x+1)(x-1)/(x+2)]=x+1
1年前
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