The nth term of an AP. Is `(3+n)/(4)`, then the sum of first 105 terms is

If the nth term of an AP is (2n +1) then the sum of its first three terms is

If the nth term of an A.P. is t_(n) =3 -5n , then the sum of the first n terms is ………

If the nth term of a AP is given by a_n=5n-3 , then the sum of first 10 terms is

The nth term of an A.P. is 7n-5, find the sum of first 20 terms of the series.

The nth term of an A.P. is p and the sum of its first n terms is q. Prove that its first term is (1)/(n)(2q-p n) .

the A.P. nth term of an A.P. is given by (-4n+15). Find the sum of first 20 terms of A.P.

The nth term of an A.P. is p and the sum of the first n term is s. Prove that the first term is (2s-pn)/(n)

The nth term of an A.P. is p, show that, the sum of its first (2n-1) terms is (2n-1)p.

The nth term of a series is 3^(n) + 2n , find the sum of first n terms of the series.