Hey, I really tried to solve this equation for a bit now, but I can't find the solution:
log(2x-5) - log (x) = 3
The solution I found was - 998/5, but I don't think that's right.. :/
It would be great if you could help me, thankyouu
How can I solve this logarithm equation?
2010-02-10 2:38 pm
回答 (4)
2010-02-10 3:14 pm
✔ 最佳答案
log(2x - 5) - log(x) = 3log[(2x - 5)/x] = 3
(2x - 5)/x = 10^3
2x - 5 = 1000x
1000x - 2x = -5
998x = -5
x = -5/998
2010-02-10 11:00 pm
I get x = -5/998 like the others but I can't see that is correct since you can't have a log of a negative number! What are people's comments?
2010-02-10 10:51 pm
log[(2x - 5)/x] = 3
(2x - 5)/x = 10^3 = 1000
1000x = 2x - 5
998x = -5
x = -5/998 = -5.0 x 10^-3
(2x - 5)/x = 10^3 = 1000
1000x = 2x - 5
998x = -5
x = -5/998 = -5.0 x 10^-3
2010-02-10 10:45 pm
log(2x-5) - log (x) = log( (2x-5) / x ) = 3
(2x-5)/x = 10^3
(2x-5) / x = 1000
2x-5 = 1000x
1000x = 2x-5
998x = -5
x = -5 / 998
(2x-5)/x = 10^3
(2x-5) / x = 1000
2x-5 = 1000x
1000x = 2x-5
998x = -5
x = -5 / 998
收錄日期: 2021-05-01 13:03:51
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100210063800AAyha5f