[" (1) If the nth term of an A.P.is "(2n+1)" ,find "],[" the sum of its first n terms "]

If the n^(th) term of an A.P.is (2n+1), find the sum of first n terms of the A.P.

If the n^(t h) term of an A.P. is (2n+1), find the sum of first n terms of the A.P.

The nth term of an A.P. is (5n-1). Find the sum of its 'n' terms.

The nth term of an A.P. is (5n-1). Find the sum of its 'n' terms.

If nth term of an A.P. is (2n+1), what is the sum of its first three terms?

If n^(th) term of an A.P.is 2n+1. Find the sum of n term.

If the n^(th) term of an A.P.is (2n+1), then the sum of its first three terms is (a) 6n+3 (b) 15 (c) 12 (d) 21

If the nth term of an A.P. is 4n-1 , find the 30th term and the sum of first 30 terms.

If the 10 th term of an A.P.is 21 and the sum of its first ten terms is 120, find its nth term.

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