Ask your own question, for FREE!
Mathematics 9 Online
OpenStudy (anonymous):

what is the sum of a 30-term arithmetic sequence where the first term is 72 and the last term is -102 A. -480 B.-450 C.-420 D.-390

OpenStudy (cwrw238):

use the formula Sn = (n/2) (a + l) where n=30, a = first term and l = last term

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!