Results 1 to 6 of 6

Thread: Factorising

  1. August 14th 2008, 09:13 AM #1
    Joker37
    Joker37 is offline
    Member
    Joined
    Aug 2008
    Posts
    179

    Smile Factorising

    Hi! I am having trouble factorising these:

    6xsquared - 11x - 35

    6xsquared - 37x + 45

    Can someone please show me worked examples to these. And sorry, I don't know how to use latex but I will learn it soon to make mathematical interpretations easier.

    Any help will be appreciated heaps!!!
    Follow Math Help Forum on Facebook and Google+
  2. August 14th 2008, 09:21 AM #2
    o_O
    o_O is offline
    Primero Espada
    o_O's Avatar
    Joined
    Mar 2008
    From
    Canada
    Posts
    1,407
    Here's a thread that demonstrates how to factor general quadratic equations: Tips on factoring, a not equal to 1

    Go through that and see what you can come up with. If you have any troubles, feel free to post again.
    Follow Math Help Forum on Facebook and Google+
  3. August 14th 2008, 09:24 AM #3
    skeeter
    skeeter is offline
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,625
    Thanks
    425
    just have to play with them a bit ...

    6x^2 - 11x - 35 = (3x + 5)(2x - 7)

    6x^2 - 37x + 45 = (3x - 5)(2x - 9)
    Follow Math Help Forum on Facebook and Google+
  4. August 14th 2008, 09:29 AM #4
    masters
    masters is offline
    He's dead, Jim
    masters's Avatar
    Joined
    Jan 2008
    From
    Big Stone Gap, Virginia
    Posts
    2,551
    Thanks
    7
    Awards
    1
    MHF Donor
    Quote Originally Posted by Joker37 View Post
    Hi! I am having trouble factorising these:

    6xsquared - 11x - 35

    6xsquared - 37x + 45

    Can someone please show me worked examples to these. And sorry, I don't know how to use latex but I will learn it soon to make mathematical interpretations easier.

    Any help will be appreciated heaps!!!
    6x^2-11x-35

    Here's what I do:

    6\times35=210

    Find 2 factors of 210 that add up to -11.

    210=2\cdot3\cdot5\cdot7

    How about -21 and 10?

    Replace -11x with -21x+10x

    6x^2-21x+10x-35

    Group the first two terms and the last two terms

    (6x^2-21x)+(10x-35)

    Factor out common factors in each group

    3x(2x-7)+5(2x-7)

    \boxed{(3x+5)(2x-7)}
    Follow Math Help Forum on Facebook and Google+
  5. August 14th 2008, 09:43 AM #5
    Joker37
    Joker37 is offline
    Member
    Joined
    Aug 2008
    Posts
    179
    Quote Originally Posted by masters View Post



    \boxed{(3x+5)(2x-7)}
    Will it still be considered correct if you put (2x-7)(3x+5) instead of (3x+5)(2x-7)?
    Follow Math Help Forum on Facebook and Google+
  6. August 14th 2008, 09:48 AM #6
    masters
    masters is offline
    He's dead, Jim
    masters's Avatar
    Joined
    Jan 2008
    From
    Big Stone Gap, Virginia
    Posts
    2,551
    Thanks
    7
    Awards
    1
    MHF Donor
    Quote Originally Posted by Joker37 View Post
    Will it still be considered correct if you put (2x-7)(3x+5) instead of (3x+5)(2x-7)?
    Absolutely. Multiplication is commutative.

    a \cdot b=b \cdot a
    Follow Math Help Forum on Facebook and Google+
« Function Question | Subtracting in base 6 »

Similar Math Help Forum Discussions

  1. factorising x^2 - x + 4
    Posted in the Algebra Forum
    Replies: 2
    Last Post: December 17th 2011, 04:23 AM
  2. Help with factorising
    Posted in the Algebra Forum
    Replies: 2
    Last Post: June 10th 2009, 12:35 PM
  3. Factorising 2
    Posted in the Algebra Forum
    Replies: 2
    Last Post: April 11th 2009, 06:28 AM
  4. factorising
    Posted in the Algebra Forum
    Replies: 1
    Last Post: February 27th 2009, 10:03 AM
  5. Factorising .
    Posted in the Math Topics Forum
    Replies: 2
    Last Post: February 15th 2009, 06:00 AM

Search Tags


/mathhelpforum @mathhelpforum