<PRE><B>Question 1029199</B>

 The first term of a geometric progression is 5 and the fifth term is 1280, the common ratio is 4 
Find the expression of the nth term? 
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a(1) = 5
r = 4
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a(5) = 5*4^x = 1280
4^x = 256
x = 4
So the exponent of the common ratio is one-less than the number of the term.
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Ans: a(n) = 5*4^(n-1)
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Cheers,
Stan H.
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