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Math Help - Solve using quadratic formula?

  1. #1
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    Solve using quadratic formula?

    Someone solve this for me pleasee solving using quadratic formula?

    please someone explain this to me and be as descriptive as possible i would really appreciate.

    4x^2-12x+9=0

    i know i have to plug them in into the quadratic formula but every time i solve this i always get a different answer and i dont get why please someone explain this to me or do it to me so i know what im doing wrong
    Last edited by mr fantastic; September 21st 2010 at 10:05 PM. Reason: Edited title.
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  2. #2
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    4x^2 - 12x + 9 = 0
    (2x - 3)(2x - 3) = 0
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  3. #3
    Senior Member Educated's Avatar
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    Quadratic formula:

    \dfrac{-b\pm\sqrt{b^2-4ac}}{2a}

    Now when you substitute values into the quadratic formula, the discriminant ( \sqrt{b^2-4ac}) determines the amount of 'roots' or answers there are because of the plus/minus before it.

    If the discriminant is above 0, there are 2 answers.
    If the discriminant is equal to 0, there is 1 answer.
    If the discriminant is below 0, there are 0 answers.

    A typical quadratic equation is:

    ax^2 + bx + c = 0

    Now from your equation, can you determine for yourself what the value of a, b and c are to put into the quadratic formula?
    Last edited by Educated; September 21st 2010 at 09:05 PM. Reason: More descriptive.
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