Предмет: Математика, автор: КурлыкКурлыковна

Сумма 10 и 16 членов арифметической прогрессии равен -8. Найти 13 член этой прогрессии.

Ответы

Автор ответа: IrkaShevko

Ответ:

-4

Пошаговое объяснение:

a₁₀ = a₁ + 9d

a₁₆ = a₁ + 15d

a₁₀ + a₁₆ = 2a₁ + 24d = 2a₁₃

a₁₃ = -8 : 2 = -4

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