Question

- The sum of n natural numbers is 5n2 + 4n.
Find its 8th term.

Please solve ​

Answer 1

Answer: 79

Step-by-step explanation:

sum of first n terms=5n^2 +4n

Sum of 1 term=9=p

Sum of two terms=28=k

2nd term =k-p=19

a=9 d=10

8th term = a+7d=79