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Math Help - (Factorials) How should I simplify this?

  1. #1
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    Red face (Factorials) How should I simplify this?

    n![(1/n-1)! - (1/n!)]


    The correct answer is apparently n-1, but I keep getting a different answer. This is what I did:


    n![(n!-(n-1)!)/(n-1)!(n!)]
    =n/(n-1)!


    Could somebody please show me what I've done wrong or what I need to do differently? any help really appreciated!
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  2. #2
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    Re: (Factorials) How should I simplify this?

    Never mind, I've figured it out now.
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  3. #3
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    Re: (Factorials) How should I simplify this?

    Quote Originally Posted by HABMD View Post
    n![(1/n-1)! - (1/n!)]
    Could somebody please show me what I've done wrong or what I need to do differently?
    I hope that you mean n!\left[\frac{1}{(n-1)!}-\frac{1}{n!}\right]. it is not what you wrote.

    That equals \left[n-1\right]
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  4. #4
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    Re: (Factorials) How should I simplify this?

    Because \frac{n!}{(n- 1)!}- \frac{n!}{n!}= \frac{n(n- 1)!}{(n- 1)!}- \frac{n!}{n!}= n- 1
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