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Math Help - Need help solving for:

  1. #16
    Super Member Quacky's Avatar
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    6x^2-5x-6
    Factors of 6 are:
    3,2
    1,6
    Factorizing then gives (2x-3)(3x+2)
    If (2x-3)(3x+2)=0,
    x=3/2 or  x=-2/3
    Which part makes it confusing? Is it the 6x^2?
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  2. #17
    MHF Contributor Drexel28's Avatar
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    Quote Originally Posted by Vuong View Post
    You could use quadratic to factor?
    I believe I just did.
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  3. #18
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    Quote Originally Posted by Quacky View Post
    6x^2-5x-6
    Factors of 6 are:
    3,2
    1,6
    Factorizing then gives (2x-3)(3x+2)
    If (2x-3)(3x+2)=0,
    x=3/2 or  x=-2/3
    Which part makes it confusing? Is it the 6x^2?
    Yes, for that I just kept trying (6x + ) (x )
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  4. #19
    Super Member Quacky's Avatar
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    Sometimes, that will give you a solution, but you must consider the other possible ways of getting 6x^2 as well.

    Factoring Quadratics
    This website is rather babyish, but the explanations are clear, and it makes factorizing a lot easier.
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  5. #20
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    How do I find the x intercepts of a problem like y=x^2-6x+25?
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  6. #21
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    Quote Originally Posted by Quacky View Post
    y=-4x^2-9x-2

    Ok, the line will cut the y axis where x=0.
    Substitute x=0 into the equation, and you get y=-2. So point of interception is at:
    (0,-2)
    Now, the line will cut the x axis where y=0. To find this, we can try to factorise:

    -4x^2-9x-2=0
    4x^2+9x+2=0
    (4x+1)(x+2)=0
    x=-2 and x=-1/4
    x intercepts are
    (-2,0) and (-1/4,0)

    Parabolas are symmetrical, so if you take the x intercepts, the line of symmetry will be halfway between them.
    -2.25/2 = -1.125 (wow, nasty numbers)
    x=-1.125 is the line of symmetry.

    A question about the vertex: Have you covered differentiation?
    Also, how would I graph this as a parabola? If both x are on the negative side
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