Question

Find the sum of n terms of the AP whose kth term is 5k+1​

Answer 1

Answer:

rxg-yqku-xoz rxg-yqku-xoz

rxg-yqku-xoz

Answer 2

Answer:

a

k

=a+(k−1)d=5k+1

⇒a+kd−d=5k+1

By compairing, d=5 & a-d=1

a=1+d

a=1+5=6

S

n

=

2

n

[2a+(n−1)d]

S

n

=

2

n

[12+(n−1)5]

S

n

=

2

n

[5n+7]