若a平方+b平方=1,ab=12/25,则a三次方减b三次方=?a四次方减b四次方=?a六次方减b六
<p>问题：若a平方+b平方=1,ab=12/25,则a三次方减b三次方=?a四次方减b四次方=?a六次方减b六<p>答案：↓↓↓<p class="nav-title mt10" style="border-top:1px solid #ccc;padding-top: 10px;">刘公致的回答：<div class="content-b">网友采纳 a²+b²=1 ab=12/25 (a-b)²=a²+b²-2ab =1-2×12/25 =1/25 a-b=±1/5 (a+b)²=a²+b²+2ab =1+2×12/25 =49/25 a+b=±7/5 a³-b³=(a-b)(a²+ab+b²) =±1/5×(1+12/25) =±37/125 a^4-b^4 =(a-b)(a+b)(a²+b²) =±1/5*(±7/5)*1 =±7/25 a^6-b^6 =(a^3-b^3)(a^3+b^3) =±37/125*(a+b)(a²-ab+b²) =±37/125*(±7/5)*(1-12/25) =±37/125*(±7/5)*13/25 =±3367/15625
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