Question 386385: Can I please get some help?
Cosider the following arithmetic sequences:
3, 7, 11, 15, 19.....
What is the 199th term a199, of this sequence.
Find the sum of the first 199 term of this sequence.
Thank you
Answer by robertb(5830)   (Show Source):
You can put this solution on YOUR website! Can I please get some help?
Consider the following arithmetic sequences:
3, 7, 11, 15, 19.....
What is the 199th term a199, of this sequence.
Find the sum of the first 199 term of this sequence.
Thank you
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an = a1 + (n-1)d;
an = 3 + (n-1)4 = 3 + 4n - 4 = 4n-1. Hence a199 = 4*199-1 = 795.
S199 = (199/2)(3+795) = (199/2)*798 = 79,401.
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