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Math Help - equations with fractions help

  1. #1
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    equations with fractions help

    Hello,

    Hoping someone can help me, i keep trying to solve this equation and i never get the right answer

    x + 1/2x = 9/5

    my method was to get rid of the fractions so the LCM is 5(2x) ?

    so multiply each term my the LCM and I end up with 10x^2 -18x + 5 = 0
    but that’s not correct because at the back of the book it says x=2 or x = 1/4

    which would mean that the original quadratic equation is 4x^2 -9x + 2 = 0
    and than that can be factored into (4x -1) (x-2)

    can anyone please tell me were I am going wrong
    thank you!
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  2. #2
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    Quote Originally Posted by hana_102 View Post
    Hello,

    Hoping someone can help me, i keep trying to solve this equation and i never get the right answer

    x + 1/2x = 9/5

    my method was to get rid of the fractions so the LCM is 5(2x) ?

    so multiply each term my the LCM and I end up with 10x^2 -18x + 5 = 0
    but that’s not correct because at the back of the book it says x=2 or x = 1/4

    which would mean that the original quadratic equation is 4x^2 -9x + 2 = 0
    and than that can be factored into (4x -1) (x-2)

    can anyone please tell me were I am going wrong
    thank you!
    Clearly the answers given by the book do NOT solve x + \frac{1}{2x} = \frac{9}{5} ....

    Your method and resulting quadratic equation is correct for x + \frac{1}{2x} = \frac{9}{5} ....


    However, I'll bet you that the equation is meant to be x + \frac{1}{2x} = \frac{9}{{\color{red}4}} ....
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  3. #3
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    Quote Originally Posted by mr fantastic View Post
    Clearly the answers given by the book do NOT solve x + \frac{1}{2x} = \frac{9}{5} ....

    Your method and resulting quadratic equation is correct for x + \frac{1}{2x} = \frac{9}{5} ....


    However, I'll bet you that the equation is meant to be x + \frac{1}{2x} = \frac{9}{{\color{red}4}} ....

    so my book is wrong?
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  4. #4
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    Quote Originally Posted by hana_102 View Post
    so my book is wrong?
    You really need to ask? Of course it's wrong!

    Solve and see what happens.

    (Does it surprise you that books can have mistakes in them?)
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