Results 1 to 2 of 2

Thread: Did I solve these logarithms correctly?

  1. #1
    Newbie
    Joined
    Aug 2010
    Posts
    17

    Did I solve these logarithms correctly?

    1. 35log[base 6](x) = 18
    My answer: x = 6^18/35

    2. 6^(-0.2x) - 3 = 7
    A bit stuck on this one. I get as far as 6^(-0.2x) = 9, but I'm a bit lost at finding the x?

    3. 7log[base 5](x) - 3 = 15
    My answer: x = 5^12/7
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    12,880
    Thanks
    1946
    1. is correct.

    2. is incorrect

    $\displaystyle 6^{-0.2x} - 3 = 7$

    $\displaystyle 6^{-0.2x} = 10$

    $\displaystyle -0.2x = \log_6{10}$

    $\displaystyle x = -5\log_6{10}$.


    3. is also wrong.

    $\displaystyle 7\log_5{x} - 3 = 15$

    $\displaystyle 7\log_5{x} = 18$

    $\displaystyle \log_5{x} = \frac{18}{7}$

    $\displaystyle x = 5^{\frac{18}{7}}$.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Did I solve this equation correctly?
    Posted in the Algebra Forum
    Replies: 5
    Last Post: Sep 29th 2010, 04:09 PM
  2. Replies: 2
    Last Post: May 27th 2010, 07:02 PM
  3. Did I solve this inequality correctly?
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: Dec 11th 2009, 06:49 AM
  4. Did I solve for h correctly?
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: Dec 11th 2009, 04:58 AM
  5. Did I solve this Integral Correctly?
    Posted in the Calculus Forum
    Replies: 2
    Last Post: Feb 20th 2009, 01:22 PM

Search Tags


/mathhelpforum @mathhelpforum