Question 370519
What is the answer to find the sum of the first 70 terms of the arithmetic sequence 45, 39, 33, 27
---
1st term: a = 45
Common difference: d = -6
n = 70
----
last = a(70) = 45+(69)(-6) = -369
S(n) = (n/2)(a + last)
-----
S(70) = (70/2)(45-369)
---
S(70) = 35(-324) = -11340
================================
Cheers,
Stan H.