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    So in this question in series in FP2

    Simplify  1/r!  - 1/(r+1)!

    And apparently this goes to  (r+1)-1/(r+1)!

    As  (r+1)! is the common denominator

    I do not understand how this is the case? Any help appreciated!
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    (Original post by Music With Rocks)
    So in this question in series in FP2

    Simplify  1/r!  - 1/(r+1)!

    And apparently this goes to  (r+1)-1/(r+1)!

    As  (r+1)! is the common denominator

    I do not understand how this is the case? Any help appreciated!
    What can (r+1)! be expanded into?
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    (Original post by Slowbro93)
    What can (r+1)! be expanded into?
     r! + 1! ?
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    (Original post by Music With Rocks)
     r! + 1! ?
    Okay, let's go back on step:

    How do you calculate: 5!, 10! and n!
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    surprised that this is a Further maths question.
    (r+1)!=(r+1) x r! which makes r! a factor
    take the example:
    4! = 4 x 3!
    so 3! is a factor of 4!
    I dont do further maths btw
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    (Original post by Slowbro93)
    Okay, let's go back on step:

    How do you calculate: 5!, 10! and n!
    ohhhhhhh...

    so  5! is  5*4*3*2*1 which is the same as  5*4!

    So then  (r+1)! is  (r+1)*r!


    Is this correct?
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    (Original post by Music With Rocks)
    ohhhhhhh...

    so  5! is  5*4*3*2*1 which is the same as  5*4!

    So then  (r+1)! is  (r+1)*r!


    Is this correct?
    Agreed!

    Now can you see what you have to do?
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    (Original post by Nayzar)
    surprised that this is a Further maths question.
    (r+1)!=(r+1) x r! which makes r! a factor
    take the example:
    4! = 4 x 3!
    so 3! is a factor of 4!
    I dont do further maths btw
    Didn't see your reply as I was busy typing mine out haha, thank you that makes sense.
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    (Original post by Nayzar)
    I dont do further maths btw
    savage
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    (Original post by Slowbro93)
    Agreed!

    Now can you see what you have to do?
    so that means that  r! is a multiple of  (r+1)*r! so therefore  (r+1)! is the common denominator

    I get it now, thank you very much
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    (Original post by Nayzar)
    surprised that this is a Further maths question.
    (r+1)!=(r+1) x r! which makes r! a factor
    take the example:
    4! = 4 x 3!
    so 3! is a factor of 4!
    I dont do further maths btw
    Oh and it is only a part of a question not a question in itself they wouldn't want it to be nice...
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    (Original post by Alexion)
    savage
    lol nah i didnt mean it like that haha
 
 
 
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