Question

Find the indicated nth partial sum of the arithmetic sequence.
8, 26, 44, 62...
n=10

Answer 1

The nth term of an arithmetic sequence is: a1 + (n-1)d
Here a1 = 8, d = 18, n = 10
10th term will be: 8 + (10-1)(18) = ?

The sum of the first n terms of an arithmetic sequence is: n * (first term + last term) / 2

Answer 2

In this case, would the last term be the 10th term?

Answer 3

yes.

Answer 4

So would the sum be 890?

Answer 5

yes.