If the sum of n terms of an A.P. is `(p n+q n^2)` , where p and q are constants, find the common difference.

If the sum of n terms of an A.P. is (pn+qn^(2)), where p and q are constants, find the common difference.

If the sum of n terms of an A.P. is n P +1/2n(n-1)Q , where P and Q are constants, find the common difference.

If the sum of n terms of an A.P. is 2n^(2)+5n , then its n^(th) term

The sum of n terms of an A.P. is 4n^(2) + 5n. Find the series.

If the sums of the first 8 and 19 terms of an A.P. are 64 and 361 respectively, find (i) the common difference and (ii) the sum of n terms of the series.

Find the sum of 'n' terms of an A.P. whose nth term is 2n+1.

Find the sum of n terms of an A.P. whose nth term is (2n+1).

If the sum of n terms of an A.P. is S_n=3n^2+5n . Write its common difference.