1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Log question

  1. Sep 24, 2004 #1
    I'm having a problem with a log question, its rather easy but I'm stuck after certain point.

    The question is:


    I tried solving by:

    ln10^(x+3) = ln5 + lne^(7-x)
    (x+3)ln10 = ln5 + (7-x)

    I am stuck after that, I've tried every combiantion and when I chack it with a calculator answer, my answer is different.

    Any help would be much appreciated, thank you.
  2. jcsd
  3. Sep 24, 2004 #2
    (x+3)ln10 = ln5 + 7-x that is correct. Now just put all of the x's to the left hand side and all the rest on the other side : xln10 + x = ln5 + 7 - 3ln10

    x(ln10 + 1) = ln5 + 7 -3ln10

    x = (ln5 + 7 - 3ln10)/(ln10 + 1)

  4. Sep 24, 2004 #3
    Ah, thank you very much. Your help is much appreciated. I could not fingure out how to get the x's out the correct way. I did not know this was allowed. Thank you again.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook