[" 143.The sum of "n" terms of the following series "],[1+(1+x)+(1+x+x^(2))+..." will be "]

Find the sum to n terms of the following series : 1+ 3x+ 5x^2+7x^3+ .......... when |x|<1.

Find the sum to n terms of the following series : 1+2x+ 3x^2+4x^3+ .......... when |x|<1.

Find the sum to n terms of the following series : 1+4x+7x^2+10x^3 + .......... when |x|<1.

The sum of n terms of the series (1)/(1 + x) + (2)/(1 + x^(2)) + (4)/(1 + x^(4)) + ……… is

The sum of n terms of the series (1)/(1 + x) + (2)/(1 + x^(2)) + (4)/(1 + x^(4)) + ……… is

Sum of n terms of the series 1+2 x+3 x^(2)+4 x^(3)+..,(x ne 1) is

The sum of first n terms of the series 1 + (1 + x) y+ (1 + x + x^(2)) y^(2) + (1 + x + x^(2) + x^(3))y^(3) + ……….. is

Sum to n terms of the series 1+(1+2)+(1+2+3)+.. ..