1. Not finding help here? Sign up for a free 30min 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!

Factorizing with no GCF

  1. Jan 12, 2008 #1
    Hi all,

    I was hoping someone could help me with factorizing an expression that has no common factors. I'm working through some pre-module work and I've never come across them before and have no idea where to start!

    They are all in the format:

    x^2 - ax - b (where there are no common factors for x, a and b)

    All I know is that when there are no common factors the GCF is 1, but thats about it :(
    Any help or good places to look to get me started are much appreciated.

    Many thanks in advance,

    Theinvoker :)
  2. jcsd
  3. Jan 12, 2008 #2


    User Avatar
    Science Advisor
    Homework Helper

    if x_1 and x_2 are zeroes to your expression x^2 - ax - b , then

    x^2 - ax - b = (x-x_1)*(x-x_2)
  4. Jan 12, 2008 #3
    Thanks for the quick reply. Im still a bit lost tho :(

    As an example:

    x^2 + 24x +133

    I can see the answer is (x + sqrt11+12)(x - sqrt11+12) by using my calculator but cant figure out how to get there.

    Many thanks again!
  5. Jan 12, 2008 #4


    User Avatar
    Homework Helper

    For the quadratic equation [itex]ax^2+bx+c=0[/itex]

    [tex]x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}[/tex]
  6. Jan 12, 2008 #5
    Ok now I feel like a right idiot lol. Many thanks couldnt see the wood for the trees! :)
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Factorizing with no GCF
  1. Factor This (Replies: 3)

  2. Factorize (Replies: 6)

  3. Factoring Cosine (Replies: 1)