几道数学计算题简算!要答案和过程!1、(1+1/3+1/5+1/7)×(1/3+1/5+1/7+1/9)-(1+1/3+1/5+1/7+1/9)×(1/3+1/5+1/7)2、(1+1/2+1/3+1/4+1/5)×(1/3+1/4+1)-(1+1/3+1/4)×(1/2+1/3+1/4+1/5)3、(1+1/5-0.1+2/15)×(0.
<p>问题:几道数学计算题简算!要答案和过程!1、(1+1/3+1/5+1/7)×(1/3+1/5+1/7+1/9)-(1+1/3+1/5+1/7+1/9)×(1/3+1/5+1/7)2、(1+1/2+1/3+1/4+1/5)×(1/3+1/4+1)-(1+1/3+1/4)×(1/2+1/3+1/4+1/5)3、(1+1/5-0.1+2/15)×(0.<p>答案:↓↓↓<p class="nav-title mt10" style="border-top:1px solid #ccc;padding-top: 10px;">黄磊光的回答:<div class="content-b">网友采纳 1.令a=1/3+1/5+1/7,b=1/3+1/5+1/7+1/9原式变为(1+a)×b-(1+b)×a=b+ab-a-ab=b-a=1/92.(1+1/2+1/3+1/4+1/5)×(1/3+1/4+1)-(1+1/3+1/4)×(1/2+1/3+1/4+1/5)=(1/3+1/4+1)×[(1+1/2+1/3+1/4+1...
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