Algebra 2

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5+(-5/2)+(5/4)

Sn=189

Find n for the given sum if the geometric series

  • Algebra 2 -

    looks like
    a = 5 and r = -1/2

    so 5((1 - (-1/2)^n)/(1-(-1/2)) = 189
    1 - (-1/2)^n = 56.7
    (-1/2)^n = -56.7

    since we know that n must be a whole number and for the above to be true, n must be odd
    so we could solve
    (1/2)^n = 56.7
    using logs,

    n = log 56.7/log .5 = a negative
    No answer to your question !!!

    There is something bogus about your question.
    (your last sentence appears incomplete)

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