To big for here down there is question.?

Question

Find s_8 , the eighth term in the series corresponding to the arithmetic sequence which has a = 5 and d = 2.

Answer 1

This depends on your definition of an arithmetic sequence.

If your subscripts start with zero, then:

s(n) = a + dn

and

s(8) = 5 + 2(8) = 5 + 16 = 21

If your subscripts start with 1 (which it sounds like they do, since you say that s_8 is the 8th term):

s(n) = a + d(n - 1)

and

s(8) = 5 + 2(7) = 19