Question

Дано: b1=5 q=2 Найти: S8 Решение:

Answer 1

Определяется по формуле
Sn=B1(1-g^2)/1-q
Подставляем
S8=5(1-2^2)делим на 1-2
Ответ 15

Answer 2

Problem Statement

We are given the values of b1 = 5 and q = 2. We need to find the value of S8.

Solution

To find the value of S8, we can use the formula for the sum of a geometric series:

S = a * (1 - q^n) / (1 - q)

Where: - S is the sum of the series - a is the first term of the series - q is the common ratio of the series - n is the number of terms in the series

In this case, we are given b1 = 5 and q = 2. We need to find S8, which means we need to find the sum of the first 8 terms of the series.

Using the formula, we can substitute the given values:

S8 = b1 * (1 - q^8) / (1 - q)

S8 = 5 * (1 - 2^8) / (1 - 2)

Simplifying the expression:

S8 = 5 * (1 - 256) / (-1)

S8 = 5 * (-255) / (-1)

S8 = 5 * 255

S8 = 1275

Therefore, the value of S8 is 1275.

Answer

The value of S8, given b1 = 5 and q = 2, is 1275.