SOLUTION: 1) determine the sum of the arithmetic series 19.5+14+8.5+...t24 2)Determine the value of t1 for an arithmetic sequence, where d=-4 and S14 = 1120

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Question 1086467: 1) determine the sum of the arithmetic series 19.5+14+8.5+...t24
2)Determine the value of t1 for an arithmetic sequence, where d=-4 and S14 = 1120
Answer by Edwin McCravy(20056)   (Show Source): You can put this solution on YOUR website!
1) determine the sum of the arithmetic series 19.5+14+8.5+...t24
t2-t1 = 14-19.5 = -5.5 = d
t3-t2 =  8.5-14 = -5.5 = d



Substitute n = 24, t1 = 19.5, and d = -5.5,
to find S24

2)Determine the value of t1 for an arithmetic sequence,
where d=-4 and S14 = 1120


Substitute n = 14, d = -4, then substitute S14 = 1120. 

Then solve for t1.

Edwin
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