Question

find the sum of 8 times and n Times of a sequence 9,-3,1,1/3​

Answer 1

Answer:

Step-by-step explanation:

First find the 40 th term:

a40=a1+(n−1)d        =2+39(3)=119

Then find the sum:

Sn=n(a1+an)2S40=40(2 + 119)2=2420