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: Basic Algebra Simplifying a complex fraction

  1. Dec 24, 2011 #1

    Femme_physics

    User Avatar
    Gold Member

    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Dec 24, 2011 #2
    Just to clarify
    [tex] C = \frac{62.5}{(x+3)(x+4)} [/tex]
    and
    [tex] R = 1 + \frac{0.625}{(x+3)(x+4)} + \frac{7}{(x+3)}[/tex]

    ?
     
  4. Dec 24, 2011 #3

    Femme_physics

    User Avatar
    Gold Member

    I don't know, I only know what I'm trying to solve not other suppositions
     
  5. Dec 24, 2011 #4

    HallsofIvy

    User Avatar
    Science Advisor

    Then I guess the question is: what are you trying to do?
     
  6. Dec 24, 2011 #5
    In the last line, I don't really see why you don't simplify by eliminating (x+3)(x+4).
     
  7. Dec 24, 2011 #6

    I like Serena

    User Avatar
    Homework Helper

    How does the smiley factor in? :smile:



    Btw, it looks right, but it would be nice if you wrote things down a bit neater.
    And you can simplify it further as micro suggested.
     
  8. Dec 24, 2011 #7

    Femme_physics

    User Avatar
    Gold Member

    Well, I just have a engineering transfer (C/R) function that I'm looking to simplify. as per title :smile: .

    The question is "am I right so far?" , basically. Just checking I didn't do a math error.

    True! I did, and went on to simplify ....
    http://img39.imageshack.us/img39/1011/cr2b.jpg [Broken]

    Can I simplifiy it even more?

    Smilies are an intensively complex algorithmic field of math. I don't even wanna get into it. Plus, somehow all my results to that end up in a frowny face :(

    You can consider this smiley as a stray. Deviating from another exercise. Sneaky little bastard..
     
    Last edited by a moderator: May 5, 2017
  9. Dec 24, 2011 #8
    Can't you just multiply out the brackets under the division line to get
    X^2 + 14x + 40.625 as the denominator
     
  10. Dec 24, 2011 #9

    Femme_physics

    User Avatar
    Gold Member

    Thing is I'm not sure if I'll consider having a power of 2 in my equation all that simplified?
     
  11. Dec 24, 2011 #10

    I like Serena

    User Avatar
    Homework Helper

    pknn17l.jpg
     
  12. Dec 24, 2011 #11

    Femme_physics

    User Avatar
    Gold Member

    rofl!
     
  13. Dec 24, 2011 #12

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    I hate to butt in, because I know that you and I like Serena have developed a rapport .

    What is the expression you are starting with?

    Is it :
    [itex]\displaystyle\frac{C}{R}=\frac{\displaystyle\frac{62.5}{(x+3)(x+4)}}{\displaystyle 1 + \frac{0.625}{(x+3)(x+4)} + \frac{7}{(x+3)}}\ \ ?[/itex]​
     
    Last edited by a moderator: May 5, 2017
  14. Dec 24, 2011 #13

    Femme_physics

    User Avatar
    Gold Member

    Last edited by a moderator: May 5, 2017
  15. Dec 24, 2011 #14

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    That result looks right, with or without the smiley.
     
  16. Dec 24, 2011 #15

    Femme_physics

    User Avatar
    Gold Member

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook