Question

find the sum to n terms of the AP, whose kth term is 5k+1​

Answer 1

Answer:

On putting k=1,we get 1st term a1=5(1)+1=6,a2=5(2)+1=11, common difference d=a2-a1=11-6=5

So sum of n terms =n/2[2(6)+(n-1)5]

=n/2(12+5n-5)

=n/2(5n+7)

=(5n^2+7n)/2

Answer 2

Answer:

I HOPE ITS HELPFUL.