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The 2nd term in Geometric sequence is -4 and the 5th is 32 ,find the general formula \term and the first 3 terms ,find the 18th term

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asked by Awe
  1. a r^0 + a r^1 + a r^2 +.... ar^(n-1)
    the 18th term is ar^17
    if a = 2 and r = -2
    then a r^17 = 2 (-2)^17
    = - 2^17 = -131072

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    posted by Damon

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