SOLUTION: express given sums in summation notation: 11+15+19+23+...+71

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Question 662130: express given sums in summation notation: 11+15+19+23+...+71
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

express given sums in summation notation: 11+15+19+23+...+71

Arithemetic Sequence:  d = 4

a%5Bn%5D+=+11+%2B+%28n-1%29d+=+71 

  11 + (n-1)4 = 71

    4n - 4 = 60

         n = 16

a%5Bn%5D+=+11+%2B+%28n-1%294+=++4n+%2B+7 

11+15+19+23+...+71 is sum%28+4n%2B7%2C+n=1%2C+16+%29