what is the sum of the first five terms of geometry series with A1 is equal to 20 and R is equal to 1/4 express your answer as an improper fraction in the lowest term without using spaces

what is the sum of the first five terms of geometry series with A1 is equal to 20 and R is equal to 14 express your answer as an improper fraction in the lowest class=

Respuesta :

You have:

a1 = 20

r = 1/4

The general expression for the sum of the first n terms of a geometric series is given by:

Sn = a1(r^n - 1)/(r - 1)

For the first five terms of the summation is:

S5 = 20((1/4)⁵ - 1)/(1/4 - 1)

S5 = 20(-0.999)/(-0.75)

S5 = 14.985

Hence, the sum of the first five terms is S5 = 14.985