A.P|| nth term||sum OF n term

A.M || G.P(nth term & sum OF n terms)

The mth term of an A.P. is n and nth term is m. Then rth term of it is

If the first,second and nth terms of a A.P. are respectively a,b and c then prove that the sum of n terms of this series is

If the mth term of an AP is 1/n and nth term is 1/m, then find the sum to mn terms.

The sum of m and n terms of an A.P. are n and m respectively. Prove that the sum of (m + n) terms will be - (m+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 (5n-1). Find the sum of its 'n' terms.

Find the sum of the first 25 terms of an A.P. whose nth term is given by a_(n)=7-3n

Find the sum of the first 25 terms of an A.P. whose nth term is given by a_(n)=2-3n