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Math Help - solving letter only equations

  1. #1
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    solving letter only equations

    solve for x

    (1/x) + (1/y) = z
    i multiplied by xy to get rid of the denominators:
    y + x = zxy
    then
    x = zxy -y

    from here i have no idea.....
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  2. #2
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    As a general rule, at least 2 equations are required to solve 2 variables. At least 3 equations are required to solve 3 variables.

    So unless you left out some other information, it is not possible to find a unique solution. The question most likely wants you to find x in terms of the other 2 variables, which you did well. From here, move the zxy over to the left and factorise x out.
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  3. #3
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    guess i should have posted the answer in the back of the book eh?

    x= (y/yz-1)

    how did they get rid of the other x?
    is this answer wrong then??
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  4. #4
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    Quote Originally Posted by t-dot View Post
    solve for x

    (1/x) + (1/y) = z
    i multiplied by xy to get rid of the denominators:
    y + x = zxy
    then
    x = zxy -y

    from here i have no idea.....
    \frac{1}{x} + \frac{1}{y} = z

    \frac{1}{x} = z - \frac{1}{y}

    x = \frac{1}{z - \frac{1}{y}}

    x = \frac{1}{\frac{yz}{y} - \frac{1}{y}}

    x = \frac{1}{\frac{yz - 1}{y}}

    x = \frac{y}{yz - 1}.
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  5. #5
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    great help.
    awesome!
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