Sum the series `1+(1+x)+(1+x+x^2)`+…….. Upto n terms.

Find the sum of the series – 1 + 5 + 11 +….to n terms.

Find the sum of the following series : 1+(1+2)+(1+2+3) + .... to n terms .

Find the sum of the following series : 1.2+2.3+3.4+ .... to n terms .

Sum of the series sum_(r=1)^(n) (r^(2)+1)r! is

Find the sum to n terms of the series : (x+1/x)^2+(x^2 + 1/x^2)^2+ (x^3 + 1/x^3)^2+ ...... .

Find the sum of n terms \ of the series: 1/(1. 2)+1/(2. 3)+1/(3. 4)+dot+ 1/n dot((n+1))

If the sum of the series 1 + (2)/(x) + (4)/(x^(2)) + (8)/(x^(3)) + …………….. is a finite number, then:

Obtain the sum of the series : 1/1.4+1/4.7+1/7.10 + .......... to n terms.

If the sum to infinity of the series 1 + 4x + 7x^2 + 10x^3 +............. is 35/16 then x= (A) 1/5 (B) 2/5 (C) 3/7 (D) 1/7