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Thread: How is it possible to find the Value of k?

  1. #1
    rcs
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    How is it possible to find the Value of k?

    Given:

    kx^2 + 5x -3 = 0, and -3 is one of the roots.

    i've been solving this using the sum and product of rryoots but it solving this does not fit the process.

    Please help me on this.
    i tried using quadratic formula, but still there is k.

    Thank you so much.
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  2. #2
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    Re: How is it possible to find the Value of k?

    $x=\dfrac{-5\pm \sqrt{25+12k}}{2k}$

    Try each (+ or -), setting it to -3 and solve for k.
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    Re: How is it possible to find the Value of k?

    Quote Originally Posted by rcs View Post
    Given: kx^2 + 5x -3 = 0, and -3 is one of the roots.
    If $-3$ is a root, we know that $k(-3)^2+5(-3)-3=0$ so solve for $k$.
    Thanks from SlipEternal and HallsofIvy
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