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    Its from edexcel jan 07

    Its a long question about arithmetic progression but you end up with this

    (3k-100)(k+35)<0

    It asks to work out the value of k. (2 marks)

    The answer is 100/3.

    Why is it only one bracket that has been used though? Shouldn't the other bracket be used too to get an answer of -35?
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    (Original post by Insanity514)
    Its from edexcel jan 07

    Its a long question about arithmetic progression but you end up with this

    (3k-100)(k+35)<0

    It asks to work out the value of k. (2 marks)

    The answer is 100/3.

    Why is it only one bracket that has been used though? Shouldn't the other bracket be used too to get an answer of -35?
    because the answer cannot be negative so you only consider the positive solution
    (you can't have a negative number of rows)
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    (Original post by Insanity514)
    Its from edexcel jan 07

    Its a long question about arithmetic progression but you end up with this

    (3k-100)(k+35)<0

    It asks to work out the value of k. (2 marks)

    The answer is 100/3.

    Why is it only one bracket that has been used though? Shouldn't the other bracket be used too to get an answer of -35?
    Well it depends on what "k" is supposed to represent. Most likely because it cannot be negative, but that's dependant on what "k" actually is.
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    Thanks guys
 
 
 
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