若a是正整數，則(3a+2)平方+4(3a+1)+4應是多少的倍數?
回答 (1)
2018-02-12 6:20 am
Sol
(3a+2)^2+4(3a+1)+4
=(3a+2)^2+4(3a+2)
=(3a+2+4)(3a+2)
=3(a+2)(3a+2)
是3的倍數
(3a+2)^2+4(3a+1)+4
=(3a+2)^2+4(3a+2)
=(3a+2+4)(3a+2)
=3(a+2)(3a+2)
是3的倍數
收錄日期: 2021-04-30 22:37:00
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https://hk.answers.yahoo.com/question/index?qid=20180211180507AAbPN4J