1. Leaka
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    Leaka Creative Mettle

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    Math Hurts My Brain

    Discussion in 'The Lounge' started by Leaka, May 5, 2008.

    Math is very confusing.
    Again I need some help with math. I need help with:
    Factoring a quadratic with leading coefficient greater than 1

    The Problem:
    6x^2+13x+6
     
  2. Cogito
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    Cogito Former Mod, Retired Supporter Contributor

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    Sure that second term isn't 12x?
     
  3. FoxyMomma
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    FoxyMomma Contributing Member

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    (2x+3)(3x+2)
     
  4. Leaka
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    Leaka Creative Mettle

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    No its X to the squared power.

    I already tried and I got the answer wrong.

    Okay let me try again:

    3y^2(y to the second power)-16y+16

    Okay um...
    4 goes into 16 and 1y might work.

    Let me see um...
    (1y+4)(4y+4)
     
  5. FoxyMomma
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    FoxyMomma Contributing Member

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    OOops, i was wrong...hang on
     
  6. Charisma
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    Charisma Transposon Contributor

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    FoxyMomma gave the right answer. Step-wise:

    6x^2+13x+6
    Method I'm using: Breaking Mid-term (In this case = 13x)
    For that:
    Sum 13
    Product 36 (Multiply 1st term and Last term)
    +9 and +4 is the correct combination. Since 9*4=36, 9+4=13.
    So
    6x^2+9x+4x+6
    3x(2x+3)+2(2x+3) - Factorization
    (3x+2)(2x+3) Factorization
     
  7. Cogito
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    Cogito Former Mod, Retired Supporter Contributor

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    (I was asking about the second term, 13x, but FoxyMama got there first with the answer to the one you asked)
     
  8. FoxyMomma
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    FoxyMomma Contributing Member

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    I can't get the 2nd one. My brain is failing me. It is possibly prime.
     
  9. Leaka
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    Leaka Creative Mettle

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    That isn't correct either.

    Um let me see uh....

    Nevermind. Let me try another:

    2z^2-3z-14
    Tow times a number to the second power minus three times a number minus fourteen

    So let me see:

    (2z-7)(3z-7)
     
  10. FoxyMomma
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    FoxyMomma Contributing Member

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    2nd one is
    (3y-4)(y-4)

    3y^2-12y-4y+16
    3y(y-4)-4(y-4)
    (3y-4)(y-4)
     
  11. FoxyMomma
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    FoxyMomma Contributing Member

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    (2z+7)(z-2)

    2z^2-4z+7z-14
    2z(z-2)7(z-2)
    (2z+7)(z-2)
     
  12. Leaka
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    Leaka Creative Mettle

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    Thanks FM.
    But I'm just going to give up on this. Its impossible for me to comprehend math.
    The funny thing is that as I have stated before English is not my native langauge, but I do better in English then math.
    But all the other foreign kids are better at math then I am.
     
  13. Mr Sci Fi
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    Mr Sci Fi Senior Member

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    All this is alien to me.

    I'm an English major here.

    You people are going to make my brain 'splode.
     
  14. FoxyMomma
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    FoxyMomma Contributing Member

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    Try splitting the middle term or multipling first term by last term (excluding exponents) and then factoring from there.
     
  15. Leaka
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    Leaka Creative Mettle

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    Okay I'll try this one:

    W divided by 6wx divided by 9w divided by 4x

    My answer:
    2 divided by 27/w

    2/27w
     
  16. Cogito
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    Cogito Former Mod, Retired Supporter Contributor

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    Leaka:

    Start by factoring the first term, and the third term. Those factors are multipliers (coefficients) for the first and second terms onf your binomials in most of these problems.

    2 can only be factored as 2*1 (in whole numbers), and 14 can either be 2*7 or 14*1

    so your x terms will probably be x and 2x, and your x^0 terms (constants) will probably be 1 and 14 or 2 and 7

    Because the first term is +, the xterms will both be positive (they could also bot be negative, but in that case we could FORCE them both to be positive.

    Likewise, because the third term is positive, the constants will either be both positive or both negative. In this case, we cannot force them, because we have already forced the x terms - you can only force once.

    BUT - because the signs ARE the same, and the second term is positive, we know that both our constants will be positive.

    So these are our most likely possibilities:
    (x+1)(2x+14)
    (x+14)(2x+1)
    (x+2)(2x+7)
    (x+7)(2x+2)

    Try each of them out to see which one gives the right center term.

    That's how most of these are soved by factoring, which I assume is the method you are expected to use at this stage. There are other methods for solving more difficult factoring problems, but you should master this one.
     
  17. Cogito
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    Cogito Former Mod, Retired Supporter Contributor

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    The other hint is that the middle term is the sum of the cross-products. You'll start to see the pattern with practice though,so I don't want to say too much more than that.

    "Give a man a fish, you feed him for a day. Teach a man to fish, you feed him for life."
     
  18. FoxyMomma
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    FoxyMomma Contributing Member

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    For some reason, I can't "see" how this one is set up. Anyway to write it differntly?

    W
    6wx ???
     
  19. Leaka
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    Leaka Creative Mettle

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    w divide sign 9w
    6wx 4x

    w times sign (.) 4x
    6wx 9w

    w . 2x
    2.3wx 3.3w
    =2
    27w


    Next one:
    An 82 degree line is attached to a kite. When the kite has pulled its line taut, the angle of the elevation to the kite is 52 degrees . Find the height of the kite. Round your answer to the nearest hundredth.
     
  20. FoxyMomma
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    FoxyMomma Contributing Member

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    Good luck with that one! I'm not good at word problems! Sorry
     
  21. Leaka
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    Leaka Creative Mettle

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    Well I can't put the triangle down.

    It goes something like:
    Sin= o
    82
    82 x 52 degrees
    52 degrees= .7880

    82 X .7880= 64.616
    =64.62
     
  22. Cogito
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    Cogito Former Mod, Retired Supporter Contributor

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    I believe you copied the problem incorrectly. This question makes more sense if 82 is a linear measure instead of degrees.

    If that is the case, your solution is correct.
     
  23. Leaka
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    Leaka Creative Mettle

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    Nope it says degreees.
     
  24. FinalConflict
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    You don't go to FLVS do you?
    Cause they tend to give you the wrong answer.

    And I just covered this for a second time(going from a Private School to a Public is not the best idea) and I still can't remember it, and if I did I'd probably give you the wrong answer cause I wouldn't know what the hell I was doing, sorry.
     

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