Results 1 to 3 of 3

Math Help - proof [(a,b),c]=([a,c],[b,c])...?

  1. #1
    Newbie
    Joined
    Dec 2009
    Posts
    12

    proof [(a,b),c]=([a,c],[b,c])...?

    I can't prove ...if a,b,c are positive integer, then

    1.) [(a,b),c]=([a,c],[b,c])

    2.) ([a,b],c)=[(a,c),(b,c)]


    .....*-*!!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Apr 2005
    Posts
    15,537
    Thanks
    1392
    Quote Originally Posted by konna View Post
    I can't prove ...if a,b,c are positive integer, then

    1.) [(a,b),c]=([a,c],[b,c])

    2.) ([a,b],c)=[(a,c),(b,c)]


    .....*-*!!
    I'm afraid you are going to have to define [x,y] and (x,y).
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Dec 2009
    Posts
    12
    Quote Originally Posted by konna View Post
    I can't prove ...if a,b,c are positive integer, then

    1.) [(a,b),c]=([a,c],[b,c])

    2.) ([a,b],c)=[(a,c),(b,c)]


    .....*-*!!

    Oh!1 sorry sorry!
    [(a,b),c]=([a,c],[b,c])=>lcm[gcd(a,b),c]=gcd(lcm[a,c],lcm[b,c])


    ([a,b],c)=[(a,c),(b,c)]=>gcd(lcm[a,b],c)=lcm[gcd(a,c),gcd(b,c)]
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 15
    Last Post: June 8th 2011, 11:13 AM
  2. Replies: 5
    Last Post: October 19th 2010, 10:50 AM
  3. [SOLVED] direct proof and proof by contradiction
    Posted in the Number Theory Forum
    Replies: 2
    Last Post: February 27th 2010, 10:07 PM
  4. Proof with algebra, and proof by induction (problems)
    Posted in the Discrete Math Forum
    Replies: 8
    Last Post: June 8th 2008, 01:20 PM
  5. proof that the proof that .999_ = 1 is not a proof (version)
    Posted in the Advanced Applied Math Forum
    Replies: 4
    Last Post: April 14th 2008, 04:07 PM

Search Tags


/mathhelpforum @mathhelpforum