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Math Help - How to make x the subject

  1. #1
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    How to make x the subject

    Hi guys.

    Stuck with this question...


    P = [mx( x +a)] / C


    Express x in terms of m, P and C and a

    Looks relatively easy but is an impossible task for me to solve it. =(

    Greatly Appreciate your help guys !

    Thanks
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  2. #2
    MHF Contributor undefined's Avatar
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    Quote Originally Posted by liukawa View Post
    Hi guys.

    Stuck with this question...


    P = [mx( x +a)] / C


    Express x in terms of m, P and C and a

    Looks relatively easy but is an impossible task for me to solve it. =(

    Greatly Appreciate your help guys !

    Thanks
    Hint: Quadratic.
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  3. #3
    Junior Member
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    Erm.

    Can you give me more Hint pls.

    I just simply cant make x an isolated variable by itself.

    It has to get stuck with one of the variables.
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  4. #4
    Super Member Bacterius's Avatar
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    Right after you multiplied each side by C (and divided by m if wanted), expand the right-hand side, what do you recognize ? Do you know the quadratic formula ?
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  5. #5
    MHF Contributor undefined's Avatar
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    Quote Originally Posted by liukawa View Post
    Erm.

    Can you give me more Hint pls.

    I just simply cant make x an isolated variable by itself.

    It has to get stuck with one of the variables.
    Have you learned the quadratic equation?
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  6. #6
    Senior Member Educated's Avatar
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    Firstly expand it. This will help in solving it.

    P = \dfrac{mx( x +a)}{C}

    P = \dfrac{mx^2 + mxa}{C}

    PC = mx^2 + mxa

    0 = mx^2 + mxa - PC

    Now put the values into the quadratic formula to get x = ...
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  7. #7
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    Quote Originally Posted by Educated View Post
    Firstly expand it. This will help in solving it.

    P = \dfrac{mx( x +a)}{C}

    P = \dfrac{mx^2 + mxa}{C}

    PC = mx^2 + mxa

    0 = mx^2 + mxa - PC

    Now put the values into the quadratic formula to get x = ...
    Thanks alot !

    i get it now

    By using the formula, i am able to get x =... !!

    Thanks !
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