A series whose `n^(th)` term is `(n/x)`, then sum of r terms will be

Find the sum of first n terms of an AP whose n^(th) term is 5-6n .find the sum of its first 20 terms

Find the sum of 'n' terms of the series whose n^(th) term is t_(n) = 3n^(2) + 2n .

Find the sum of 'n' terms of the series whose n^(th) term is t_(n) = 3n^(2) + 2n .

The sum of n terms and sum of 100 terms of the series whose k^(th) term is (k)/(k^(4)+k^(2)+1) , will be :

Find the sum of the series whose n^(th) term is as following: n^(3)-3n