解log9(4x-1)-log9(x+1)=1/2
若log2=a log3=b
answer??
幫幫忙 log數
2012-04-06 9:26 am
回答 (2)
2012-04-06 3:25 pm
✔ 最佳答案
解log9_(4x－1)－log9_(x+1)=1/2，若log2=a，log3=b，answer??Sol
log9_(4x－1)－log9_(x+1)=1/2
log(4x－1)/log9－log(x+1)/log9=1/2
log(4x－1)－log(x+1)=log3
(4x－1)/(x+1)=3
4x－1=3x+3
x=4
2012-04-07 6:22 am
[log(4x-1)]/log9-[log(x+1)]/log9=1/2
log[(4x-1)/(x+1)]/log9=1/2
2log[(4x-1)/(x+1)]=log9
(4x-1)/(x+1)=3
4x-1=3x+3
x=4
log[(4x-1)/(x+1)]/log9=1/2
2log[(4x-1)/(x+1)]=log9
(4x-1)/(x+1)=3
4x-1=3x+3
x=4
收錄日期: 2021-05-02 10:44:26
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20120406000051KK00067