Question

sum of first n natural terms is ​

Answer 1

sn = n/2 ×2a+n-1 ×d.........

Answer 2

Answer:

Step-by-step explanation:

sum of n natural numbers = n(n+1)/2

example:

sum of first 100 natural numbers =100×(100+1)/2

=100×101/2

=10100/2

=5050