Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How to you solve this simple algebra?

  1. Feb 13, 2010 #1
    This isn't a homework question...just something I picked up on a finance book about dividends. Say you have something like this.

    $30.85 = X/$1.15 + X/($1.15)^2

    How do I solve for x step by step? They give me an answer of $18.98 and if I sub that # into x I get 30.85. How do I do it the other way...algebraically?

    Thanks.
     
    Last edited: Feb 13, 2010
  2. jcsd
  3. Feb 13, 2010 #2

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    Welcome to PF!

    Hi EdLeafs ! Welcome to PF! :smile:

    (try using the X2 tag just above the Reply box :wink:)
    Easy … use brackets

    30.85 = X(1/1.15 + 1/1.152) … take it from there. :smile:
     
  4. Feb 13, 2010 #3

    HallsofIvy

    User Avatar
    Science Advisor

    The first thing I would do is multiply both sides by 1.15 to get rid of the fractions!

    (1.15)2(30.85)2= (1.15)X+ X= 2.15X

    Now divide both sides by 2.15.

    I'm wondering what X represents that dividing by "dollars" results in "dollars"! It has units of "dollars squared"?
     
    Last edited by a moderator: Feb 14, 2010
  5. Feb 13, 2010 #4

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    (erm)2 :redface:
     
  6. Feb 13, 2010 #5
    Ahh...I see. thanks a lot.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook