Sum of series `1 + 2x + 7x^2 + 20x^3 + ........` up to n terms when `x = - 1` is

The sum of series 1 + 2x + 3x^(2) + 4x^(3) + ...... up to infinity when x lies between 0 and 1 i.e., 0 lt x lt 1 is

Find the sum of the series 1+3x+5x^2+7x^3+.......... upto n terms.

Find the sum of the series 1+3x+5x^2+7x^3+.......... upto n terms.

If the sum to infinity of the series 1 + 4x + 7x^2 + 10x^3 +............. is 35/16 then x=

Find the sum of the series 1+3x+5x^(2)+7x^(3)+...... upto n terms.

Find the sum of the series 1 + (1 + x) + (1 + x + x^2) + ... to n terms, x≠ 1

Sum up to n terms the series 1+ 2x + 3x^(2) + 4x^(3) + ...

Find the sum of the series 1+4x+ 7x^(2)+ ... to n terms . Hence write down the sum to infinity when x lt 1 numerically .

Sum to n terms the series : 2+5x + 8x^2+11x^3+........., |x| < 1 .