Предмет: Математика, автор: Iquotti

Дана геометрическая прогрессия: 10; -30; ...
Определите третье значение!
b3=

Ответы

Автор ответа: mihalahik2010
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Вячеслав001

28.02.2017

Алгебра

5 - 9 классы

відповів/ла • перевірена експертами

Найдите первый член геометрической прогрессии (bn), если b3=18 и b6=486

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Відповідь, перевірена експертами

5,0/5

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ShirokovP

главный мозг

10.4 тис. відповіді

17.4 млн користувачів, які отримали допомогу

b1 *q^2 = 18

b1*q^5 = 486

b1 = 18/q^2

18/q^2 * q^5 = 486

b1 = 18/q^2

18q^3 = 486

b1 = 18/q^2

q^3 = 27

b1 = 18/q^2

q = 3

b1 = 18/9 = 2

q = 3

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