SOLUTION: find the indicated nth partial sum of the arithetic sequence: 11,17,23,29,...,n= 30

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Question 300447: find the indicated nth partial sum of the arithetic sequence: 11,17,23,29,...,n= 30
Answer by Fombitz(32388) About Me  (Show Source):
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+a1=11
a2=17=a1%2B6
+a3=23=a1%2B6%2B6=a1%2B%283-1%29%2A6
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+an=a1%2B%28n-1%29%2A6
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+a30=a1%2B%2830-1%29%2A6
The 30th term would be
a30=11%2B%2829%29%2A6=185
The sum of the terms from 1 to 30 would be the sum of 30 multiplied by 11 plus the 6 multiplied by the sum from 1 to 29.
s=30%2A11%2B6%2A%2829%2830%29%29%2F2=330%2B2610=2940