meili 发表于 2022-10-27 15:49:02

已知实数a,b,c,满足a+b+c=1,1/a+b-c+1/b+c-a+1/c+a-b=1,则abc=_____

<p>问题:已知实数a,b,c,满足a+b+c=1,1/a+b-c+1/b+c-a+1/c+a-b=1,则abc=_____
<p>答案:↓↓↓<p class="nav-title mt10" style="border-top:1px solid #ccc;padding-top: 10px;">郎永强的回答:<div class="content-b">网友采纳  1/(1-2a)+1/(1-2b)+1/(1-2c)  =(1-2a-2b+4ab+1-2a-2c+4ac+1-2b-2c+4bc)/(1-2a)(1-2b)(1-2c)  =(3-4(a+b+c)+4ab+4ac+4bc)/(1-2a)(1-2b)(1-2c)  =(-1+4ab+4ac+4bc)/((1-2a-2b+4ab)(1-2c))  =(-1+4ab+4ac+4bc)/(1-2c-2a+4ac-2b+4bc+4ab-8abc)  =1  -1+4ab+4ac+4bc=1-2(a+b+c)+4ac+4bc+4ab-8abc  -1=1-2-8abc  abc=0
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