SOLUTION: How can I write the following sequence in sigma notation? 6+16+26+36?

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Question 970884: How can I write the following sequence in sigma notation? 6+16+26+36?
Found 2 solutions by MathLover1, MathTherapy:
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
Notice this is an arithmetic series. Must use the formula to find the explicit formula.
d+=+10 is common difference between each two consecutive terms,
first term is 6 and counting the terms, the fourth term is 36+; so, the number of the terms is n=1,2,3,4
then nth term formula is:
6%2B+%28n+-+1%2910 where n=1,2,3,4
check:
if n=1
6%2B+%281+-+1%2910+=6%2B0=6
if n=2
6%2B+%282+-+1%2910+=6%2B10=16
if n=3
6%2B+%283+-+1%2910+=6%2B20=26
if n=4
6%2B+%284+-+1%2910+=6%2B30=36
then
sum%286%2B+%28n+-+1%2910=6%2B16%2B26%2B36=84%2C1%2C4%29

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!
How can I write the following sequence in sigma notation? 6+16+26+36?
highlight_green%28highlight_green%28sum%28%2810n+-+4%29%2Cn=1%2C4%29%29%29