数学学习乐园讨论与解答（41―50） 标签：速算与巧算
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,Arial">43</font></b><b><font face=" ,Arial"> </font></b></p><p><font face=" ,Arial">24</font><font face=" ,Arial">25</font><font face=" ,Arial">24</font><font face=" ,Arial">n</font><font face=" ,Arial" size="2">2</font><font face=" ,Arial">-1</font><font face=" ,Arial">(</font><font face="宋体" lang="ZH-CN">图</font><font face=" ,Arial">1)</font></p><p><font face=" ,Arial">3</font><font face="宋体" lang="ZH-CN">×</font><font face=" ,Arial">3</font><font face=" ,Arial">9</font><font face=" ,Arial">A</font><font face=" ,Arial">B</font><font face=" ,Arial">8</font></p><p><font face=" ,Arial">8</font><font face=" ,Arial">(</font><font face="宋体" lang="ZH-CN">图</font><font face=" ,Arial">2)</font><font face=" ,Arial">1</font></p><p><font face=" ,Arial">3</font><font face="宋体" lang="ZH-CN">×</font><font face=" ,Arial">3</font><font face=" ,Arial">3</font><font face=" ,Arial">PQ</font></p><p><font face=" ,Arial">4(1)</font><font face=" ,Arial">12.13</font><font face=" ,Arial">PQ</font><font 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,Arial">76</font></p><p><b><font face=" ,Arial"> </font></b></p><p><b><font face=" ,Arial">46</font></b></p><p><b><font face=" ,Arial"> </font></b></p><p><font face=" ,Arial">AB</font><font face=" ,Arial">AC</font></p><p><font face="宋体" lang="ZH-CN"></font></p><p><b><font face=" ,Arial"> </font></b></p><p><b><font face=" ,Arial">47</font></b></p><p><b><font face=" ,Arial"> </font></b></p><p><font face="宋体" lang="ZH-CN"></font></p><p><font face=" ,Arial">C</font><font face=" ,Arial">C</font><font face=" ,Arial">AC</font><font face=" ,Arial">BC</font><font face=" ,Arial">B</font><font face=" ,Arial">C</font><font face=" ,Arial">A</font><font face=" ,Arial">C</font><font face=" ,Arial">90</font><font face=" ,Arial">A</font><font face=" ,Arial">C</font><font face=" ,Arial">B</font><font face=" ,Arial">C</font></p><p><b><font face=" ,Arial"> </font></b></p><p><b><font face=" ,Arial">48</font></b></p><p><b><font face=" ,Arial"> </font></b></p><p><font face=" ,Arial">(1)A</font><font 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</font></b></p><p><b><font face=" ,Arial">50</font></b></p><p><b></b></p><p><b><font face=" ,Arial"> </font></b></p><p><font face=" ,Arial">15</font></p><p><font face="宋体" lang="ZH-CN"></font></p>
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