find the 139th term of the arithmetic sequence whose first term is - 28 and the common difference is 1/3

18

Step-by-step explanation:

The general formula for an arithmetic progression is a (n) = a (0) + d (n - 1), where a (0) is the first term, n is the index (counter), and d is the common difference between terms.

Here we have a (n) = - 28 + (1/3) (n - 1)

and the 139th term is a (139) = - 28 + (1/3) (138) = - 28 + 46 = 18