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: Factor expression A so that it looks like expression B

  1. Oct 11, 2012 #1
    1. The problem statement, all variables and given/known data
    This question stems from this one: https://www.physicsforums.com/showthread.php?t=642712

    I think I know how to solve it now. The only problem is I have to show how to factor this expression in to the form WolframAlpha shows.

    [itex]-a^2 b + a b^2 + a^2 c - b^2 c - a c^2 + b c^2[/itex] → [itex]-(a-b)(a-c)(b-c)[/itex]
    2. Relevant equations
    3. The attempt at a solution

    I did this but then I don't know how to proceed.

    [tex]ab(b-a)+ac(a-c)+bc(c-b)[/tex]

    Please help. Thanks
     
  2. jcsd
  3. Oct 11, 2012 #2
    By rearranging it like so:
    [itex]−a^2b+ab^2+a^2c−b^2c−ac^2+bc^2 \rightarrow −a^2b+a^2c+ab^2−ac^2−b^2c+bc^2 [/itex]
     
    Last edited: Oct 11, 2012
  4. Oct 11, 2012 #3
    You're a genius! Thank you. :)
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook