Determine the number of terms n in each arithmetic series. a₁=14 d=10 sn= 1260 i know the answer is 15, i'm just not sure how to get there.

We're given an arithmetic sequence that starts with and a common difference between terms of . Recursively, this sequence is given by

We can find an explicit formula for the -th term :

and so on, with the general pattern of

We're given that the sum of the first consecutive terms is

Recall that

So we solve for :

(there are two solutions, but only one is a positive integer)

a

step-by-step explanation:

its wrong