更新1:
without calculator and show steps
Log question?
回答 (4)
2016-09-26 11:47 am
✔ 最佳答案
（log20+3log5+2log2）/ log3√27=2(log20+3log5+2log2)/(2log3√27)
=2(log20+3log5+2log2)/log(9*27)
=2[log2+1+3(1－log2)+2log2]/(5log3)
=8/(5log3)
2016-10-22 11:56 am
( log20+3log5+2log2）/ log3√27
=(1+log 2+3 log 5+2 log 2)/(log 3+1.5 log 3)
=2(1+3 log 2+3 log 5)/(2 log 3+3 log 3)
=2(1+3)/(5 log 3)
=8/(5 log3)
=(1+log 2+3 log 5+2 log 2)/(log 3+1.5 log 3)
=2(1+3 log 2+3 log 5)/(2 log 3+3 log 3)
=2(1+3)/(5 log 3)
=8/(5 log3)
2016-09-27 2:45 pm
( log20+3log5+2log2）/ log3√27
= [log(4*5)+3log5+2log2] / log[3*(3^3/2)]
= (log2²+log5+3log5+2log2) / log(3^5/2)
= (2log2+4log5+2log2) / (5/2)log3
= (4log2+4log5) / (5/2)log3
= 4log(2*5) / (5/2)log3
= (8/5)(log10) / log3
= 8 / (5log3) . . . . . . . . . . . . .〔∵ log10 = 1〕
~~~~~~~~~~~~~~~~~~ THE END ~~~~~~~~~~~~~~~~~~~~~
Formulae :-
------------
log x + log y = log xy
log x^y = y log x
= [log(4*5)+3log5+2log2] / log[3*(3^3/2)]
= (log2²+log5+3log5+2log2) / log(3^5/2)
= (2log2+4log5+2log2) / (5/2)log3
= (4log2+4log5) / (5/2)log3
= 4log(2*5) / (5/2)log3
= (8/5)(log10) / log3
= 8 / (5log3) . . . . . . . . . . . . .〔∵ log10 = 1〕
~~~~~~~~~~~~~~~~~~ THE END ~~~~~~~~~~~~~~~~~~~~~
Formulae :-
------------
log x + log y = log xy
log x^y = y log x
2016-09-27 3:10 am
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收錄日期: 2021-04-18 15:35:03
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20160926031905AAvMiBU