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Math Help....

umer007
in Analysis and Calculus

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The arithmetic sequence a, a+d, a+2d, a+3d,...., a+(n-1)d has the following properties:

 

When the first, third, and fifth and so on terms are added, up to and including the last term, the sum is 320.

 

When the first, fourth, seventh and so on terms are added, up to and including the last term, the sum is 224?

 

What is the sum of the whole sequence?

 

Im clueless, can ne1help.

 

Thx alot.

It depends on how many terms are in the sequence. Assuming that the last term is a+(n-1)d, you get the values:

 

a=512/(n+1)

d=-192/(n2+n)

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