The sum of the first three terms of an arithmetic progression is 9 and the sum of their squares is 35. The sum of the first n terms of the series can be

If the sum of the first n terms of the series

The sum of the first three terms of an increasing G.P.is 21 and the sum of their squares is 189. Then the sum of the first n terms is

The sum of the first three terms of an increasing G.P. is 21 and the sum of their squares is 189. Then the sum of its first n terms is

The sum of the first three terms of an increasing G.P. is 21 and the sum of their squares is 189. Then the sum of its first n terms is

. The sum of the first three terms of an increesing G.P. is 21 and the sum of their squares is 189. Then the sum of its first n terms is

The sum of the first three terms of an A.P. is 9 and the sum of their squares is 35. The sum to first n terms of the series can be

The sum of the first three terms of the arithmetic progression is 30 and the sum of the squares of the first term and the second term of the same progression is 116. Find the seventh term of the progression if its fith term is known to be exactly divisible by 14.

The sum of the terms of an infinite geometric progression is 3 and the sum of the squares of the terms is 81. Find the first term of the series.

If the sum of the first 4 terms of an arithmetic progression is p, the sum of the first 8 terms is q and the sum of the first 12 terms is r, express 3p+r in terms of q.

The sum of the first three consecutive terms of an A.P. is 9 and the sum of their squares is 35. Find S_(n)