Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
Help solving a log problem 10 points?
log (base b) x - log (base b) 5 = log (base b) 2 - log (base b) (x-3)
Thank you!
3 Answers
- NoneLv 78 years agoFavorite Answer
since all the logs are to the same base,
log (b) x - log (b) 5 = log (b) 2 - log (b) (x-3)
x/5 = 2/(x - 3)
x^2 - 3x = 10
x^2 - 3x - 10 = 0
(x - 5)(x + 2) = 0
x = 5, -2
- 8 years ago
Well, since the logs are subtracting, you set them up to divide.
log(base b) x/5 =log (base b) 2/x-3
Since the logs have the same base, you can cancel them out which leaves you with
x/5=2/x-3
You then "cross multiply" and get x^2-3x=10
Move the 10 over and set it equal to 0.
Then factor (x-5)(x+2)
And so on. The answer can't make log negative.
Source(s): AP PreCalc - 8 years ago
logx-log5=log(x/5) and log2-log(x-3)=log(2/(x-3))
so x/5=2/(x-3) this implies x^2-3x-10=0 -> (x-5)(x+2)=0 implies x=5 or x=-2
