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<h1 class="title">MH-20210116</h1>
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<li><a href="#原解" id="toc-原解"><span class="toc-section-number">1</span> 原解</a></li>
<li><a href="#扩展" id="toc-扩展"><span class="toc-section-number">2</span> 扩展</a></li>
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<h1 data-number="1" id="原解"><span class="header-section-number">1</span> 原解</h1>
<pre><code>1 * 5 = 5
2 * 4 = 8
3 * 3 = 9</code></pre>
<h1 data-number="2" id="扩展"><span class="header-section-number">2</span> 扩展</h1>
<pre><code>6 = 3 + 3 = 3 + 3 + 1 - 1 = 3 + 1 + 3 - 1 = (3 + 1) + (3 - 1)
(3 + 1) * (3 - 1) = 3 * 3 + 3 * (-1) + 1 * 3 + 1 * (-1) = 3 * 3 + 1 * (-1) = 3 * 3 - 1 ^ 2 = 3 ^ 2 - 1 ^ 2
3 ^ 2 > 3 ^ 2 - 1 ^ 2</code></pre>
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