Question

Please find sum of n terms of gp

Answer 1

S = (2/3 + 2/3^3 + 2/3^5 + ...... ) + (5/3^2 + 5/3^4 + .......)

S = A + B

1) A = 2/3 + 2/3^3 + 2/3^5 + ......

   first term a1 = 2/3

   common ratio r1 = 1/3^2

A = a1/(1-r1) = 2/3/(1-1/9) = (2/3)  / (8/9) = (2*9) / (3*8) = 3\4

2) B = 5/3^2 + 5/3^4

 first term a2 = 5/3^2

 common ratio r2 = 1/3^2

B = a2/(1-r2) = (5/9) / (1-1/9) = (5*9) / (8*9) = 5/9

so, S = 3/4 + 5/9 = 38/36     Ans...

Answer 2

Step-by-step explanation:

Sn in gp= a(rⁿ-1)/r-1

HOPE IT HELPS