Find the sum of first 15 terms of an A.P. whose nth term is 9-5n.
Answers
Answered by
9
-465 is the answer.
put 1,2,3, values in nth term u will get C.D and now find Sn term by putting n= 15 in n/2(2a+(n-1)D).
put 1,2,3, values in nth term u will get C.D and now find Sn term by putting n= 15 in n/2(2a+(n-1)D).
Similar questions