Question

solve this Question please

Answer 1

1)The nth term is 2n+1 and the (n+1)th term is 2(n+1)+1

= 2n+ 2 +1

=2n + 3

So common difference is 2n+3-(2n+1)

=2

And, hence the answer is 2.

2) The first term is 2×1+1=3

And the nth term is 2n+1.

So Sum of n terms = (3+2n+1)×n/2

= (2n+4)×n/2

= n(n+2)