1:1  11-30 [数学]范老师教大家巧去绝对值
推荐理由：求值问题大部分学生会先化简，再求值，往往不去考虑字母的取值。此题，范老师教你利用已知条件巧去绝对值，教会我们不要对解题方法死搬硬套，要灵活运用！ 讲解人：http://www.jiandan100.cn/teacher/f6bde55ee0bc42adac11fef663fb1257/ ，北京五中数学教师，常年辅导数学竞赛。 题面：已知a=1999，则  =__________．
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通过问题，要学会“活学活用”！ ------------------------------------------------------------------------------------------------------------------------------------------------------------------ 查看更多本年级每周一题，请点击：http://www.jiandan100.cn/bbs/upload/forumdisplay.php?fid=376& 浏览本期“简单学习电子周报”完整目录：http://www.jiandan100.cn/bbs/upload/viewthread.php?tid=653784 |
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