Questions on Sum of n terms in A.P.

Question on nth terms in A.P.

If in an A.P. the sum of m terms is equal to n and the sum of n terms is equal to m then prove that the sum of (m+n) terms is -(m+n)

Consider the A.P. 50,48,46,44 ……. If S _(n) denotes the sum to n terms of this A.P. then

In an A.P,the sum of m terms of an AP is n and sum of n terms of AP is m,then prove that sum of (m+n) terms of AP is-(m+n)

If in an A.P. the sum of m terms is equal of n and the sum of n terms is equal to m , then prove that the sum of -(m+n) terms is (m+n) .

The sum of first n terms of an A.P. is 5n-n^2 . Find the n t h term of this A.P.

If the sum of first n terms of an A.P. is cn^(2) then the sum of squares of these n terms is

The sum of first n terms of an A.P. is 3n^2+4n . Find the 25 t h term of this A.P.

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