Question

how many terms does the ap -15,-12,-9………..15 have?​

Answer 1

Step-by-step explanation:

Last term(L) = 15; first term(a) = –15 and common difference is –12-(–15) = 3.

Then,

L = a+(n–1)d

15 = –15+(n–1)3

15+15 = 3n–3

30+3 = 3n

11 = n