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Math Help - This equation has two roots

  1. #1
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    This equation has two roots

    3x^(6)e^(-2x)-9x^(7)e^(-2x)=0 has two roots

    Where do I even start?
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  2. #2
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    Re: This equation has two roots

    I would start by dividing through by any non-zero numbers that are common to both sides of the equation. (I presume you know that e^x is not 0 for ny x.)
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  3. #3
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    Re: This equation has two roots

    Quote Originally Posted by RD33 View Post
    3x^(6)e^(-2x)-9x^(7)e^(-2x)=0 has two roots
    Where do I even start?
    Factor it: 3x^6e^{-2x}(1-3x)=0~.
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  4. #4
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    Re: This equation has two roots

    Ok I got the answer 0 and 1/3 but how did you factor it. Where does the (1-3x) come from?
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    Re: This equation has two roots

    Quote Originally Posted by RD33 View Post
    Ok I got the answer 0 and 1/3 but how did you factor it. Where does the (1-3x) come from?
    Can you factor 3a^6b-9a^7b~? What do you get?
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