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Math Help - Am I wrong or are the answers off?

  1. #1
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    Am I wrong or are the answers off?

    They say the answers for 25, and 28 are both 0 but that's not what I get. Can someone please verify this. Thanks.
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  2. #2
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    Re: Am I wrong or are the answers off?

    Herllo, thatsmessedup!

    You are right!


    They say the answers for 25 and 28 are both 0. . They are wrong!.

    25.\;\frac{x}{x-1} - \frac{x}{1-x}

    \frac{x}{x-1} - \frac{x}{1-x} \;=\;\frac{x}{x-1} - \frac{x}{\text{-}(x-1)} \;=\;\frac{x}{x-1} + \frac{x}{x-1} \;=\;\frac{2x}{x-1}




    28.\;\frac{1}{(x-1)(x-2)} + \frac{1}{(x-2)(x-3)}

    \frac{1}{(x-1)(x-2)}\cdot\frac{x-3}{x-3} + \frac{1}{(x-2)(x-3)}\cdot\frac{x-1}{x-1}

    . . . =\;\frac{x-3}{(x-1)(x-2)(x-3)} + \frac{x-1}{(x-1)(x-2)(x-3)}

    . . . =\;\frac{(x-3) + (x-1)}{(x-1)(x-2)(x-3)}

    . . . =\;\frac{2x-4}{(x-1)(x-2)(x-3)}

    . . . =\;\frac{2(x-2)}{(x-1)(x-2)(x-3)}

    . . . =\;\frac{2}{(x-1)(x-3)}
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  3. #3
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    Re: Am I wrong or are the answers off?

    Quote Originally Posted by Soroban View Post
    Herllo, thatsmessedup!

    You are right!



    \frac{x}{x-1} - \frac{x}{1-x} \;=\;\frac{x}{x-1} - \frac{x}{\text{-}(x-1)} \;=\;\frac{x}{x-1} + \frac{x}{x-1} \;=\;\frac{2x}{x-1}





    \frac{1}{(x-1)(x-2)}\cdot\frac{x-3}{x-3} + \frac{1}{(x-2)(x-3)}\cdot\frac{x-1}{x-1}

    . . . =\;\frac{x-3}{(x-1)(x-2)(x-3)} + \frac{x-1}{(x-1)(x-2)(x-3)}

    . . . =\;\frac{(x-3) + (x-1)}{(x-1)(x-2)(x-3)}

    . . . =\;\frac{2x-4}{(x-1)(x-2)(x-3)}

    . . . =\;\frac{2(x-2)}{(x-1)(x-2)(x-3)}

    . . . =\;\frac{2}{(x-1)(x-3)}
    Of course, this is implying that \displaystyle \begin{align*} x \neq \left\{ 1, 2, 3 \right\} \end{align*}.
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  4. #4
    Senior Member Paze's Avatar
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    Re: Am I wrong or are the answers off?

    Quote Originally Posted by Prove It View Post
    Of course, this is implying that \displaystyle \begin{align*} x \neq \left\{ 1, 2, 3 \right\} \end{align*}.
    Still means that the answer will never be 0, right?
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  5. #5
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    Re: Am I wrong or are the answers off?

    Quote Originally Posted by Paze View Post
    Still means that the answer will never be 0, right?
    Yes
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  6. #6
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    Re: Am I wrong or are the answers off?

    I'm actually get this practice exam from here Glendale Community College : Sample Tests and Study Packets which is ridiculous!
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