Results 1 to 8 of 8

Math Help - Factor by grouping

  1. #1
    Newbie
    Joined
    Oct 2008
    Posts
    22

    Factor by grouping

    Cant seem to figure this out. Any ideas or tips? Thanks for the help
    Attached Files Attached Files
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Member
    Joined
    May 2008
    Posts
    75
    Hi! 1 is a root of your polynomial, so by polynomial long division you can find out the factors.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    May 2008
    Posts
    75
    -1 is also a root (one checks this by trying the factors of the constant coefficient -1).
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Newbie
    Joined
    Oct 2008
    Posts
    22
    So if Im getting the answer of C is that wrong?
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Member
    Joined
    May 2008
    Posts
    75
    Of course that is wrong, C neither has the root 1 nor the root -1.
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Newbie
    Joined
    Oct 2008
    Posts
    22
    Ok I redid it and think I got the right answer, I first took

    2x^3 + x^2 - 2x - 1

    (2x^3 + x^2) - (2x - 1)

    x^2( 2x + 1) + 1(2x + 1) found the common factor(not sure if thats the right term)

    So my final answer would be

    (2x + 1)(x^2 +1) Again this is factoring by grouping so if anyone has any input thanks
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Member
    Joined
    May 2008
    Posts
    75
    It is not right, for the same reason as in the previous post. The - in the second row should be a plus, then it will work out. But the method is right and effective.
    Follow Math Help Forum on Facebook and Google+

  8. #8
    Newbie
    Joined
    Oct 2008
    Posts
    22
    Dangit, Ok Ill try doing this again, just not getting it
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Factor by grouping (don't understand it)
    Posted in the Algebra Forum
    Replies: 3
    Last Post: February 9th 2009, 03:03 AM
  2. Please help Factor by grouping problem
    Posted in the Algebra Forum
    Replies: 2
    Last Post: October 11th 2008, 02:40 PM
  3. Grouping polynomials to show a common factor
    Posted in the Algebra Forum
    Replies: 4
    Last Post: January 17th 2008, 07:53 PM
  4. Factor by grouping
    Posted in the Algebra Forum
    Replies: 5
    Last Post: October 13th 2007, 07:29 PM
  5. Factoring By Grouping
    Posted in the Algebra Forum
    Replies: 1
    Last Post: September 25th 2007, 07:48 PM

Search Tags


/mathhelpforum @mathhelpforum