文档分类
?a4?b4?2a2b2?442223. 解:?b?c?2bc得:a4?b4?c4?a2b2?b2c2?a2c2 (4
?a4?c4?2a2c2?分)
?a2b2?b2c2?ab2c?22222又:?bc?ac?abc得:a2b2?b2c2?a2c2?ab2c?abc2?a2bc (8
??a2b2?a2c2?a2bc分)
得:a4?b4?c4?ab2c?abc2?a2bc;所以a4?b4?c4abc≥a?b?c 分)
(10
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