Arithmetic Series

Question

The sum of the first 15 terms of an arithmetic sequence is 480. Find the 8th term of the sequence. 

Answer 1

Once we reach the 15th term we will

have added the common difference, d, 

to the first term, a_{1, 14 times:}

a₁ + 14d = 480

 

To finish we need the value of a₁