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Math Help - Using the Quadratic Formula???

  1. #1
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    Using the Quadratic Formula???

    I am having difficulty with the following problem because I do not know how to use the quadratic formula. Can anyone explain step by step on how to do the following problem using the quadratic formula?

    x^2/(2.00-x)(1.00-x) = .64

    Any input will be greatly appreciated. Thank you.
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  2. #2
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    Quote Originally Posted by confused20 View Post
    I am having difficulty with the following problem because I do not know how to use the quadratic formula. Can anyone explain step by step on how to do the following problem using the quadratic formula?

    x^2/(2.00-x)(1.00-x) = .64

    Any input will be greatly appreciated. Thank you.
    \frac{x^2}{(2 - x)(1 - x)} = 0.64

    x^2 = 0.64(2 - x)(1 - x)

    x^2 = 0.64(2 - 3x + x^2)

    x^2 = 1.28 - 1.92x + 0.64x^2

    0.36x^2 + 1.92x - 1.28 = 0

    Now a = 0.36, b = 1.92, and c = -1.28

    -Dan
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  3. #3
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    How did you arrive at .36x^2?

    Thank you a great deal for your response. Can you please tell me how you arrived at .36x^2? I am having difficulty understanding what operation you did to arrive at that figure. Thanks once again for your replay.
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  4. #4
    Forum Admin topsquark's Avatar
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    Here it is along with the extra step:

    \frac{x^2}{(2 - x)(1 - x)} = 0.64

    x^2 = 0.64(2 - x)(1 - x)

    x^2 = 0.64(2 - 3x + x^2)

    x^2 = 1.28 - 1.92x + 0.64x^2
    =====================================
    x^2 - 0.64x^2 + 1.92x - 1.28 = 0
    =====================================

    0.36x^2 + 1.92x - 1.28 = 0

    Now a = 0.36, b = 1.92, and c = -1.28

    -Dan
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  5. #5
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    Thank you once again for your replay. To get .36x^2 from .64x^2 do you just subtract by .28? If so, what is the reason that you subtract by .28? Thank you again for all your help.
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  6. #6
    Forum Admin topsquark's Avatar
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    Quote Originally Posted by confused20 View Post
    Thank you once again for your replay. To get .36x^2 from .64x^2 do you just subtract by .28? If so, what is the reason that you subtract by .28? Thank you again for all your help.
    Look at the coefficients oftthe x^2 terms. They are 1 and 0.64 respectively. Then 1 - 0.64 = 0.36.

    -Dan
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