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найдите сумму членов геометрической прогрессии со второго по пятый если в 1=8 и д=1/2
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Предмет:
Алгебра -
Автор:
elliotth7w - 5 лет назад
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Ответы 1
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b₁=8 q=1/2 S₂₋₅=?
b₂=b₁q=8*(1/2)=4.
b₃=b₂q=4*(1/2)=2.
b₄=b₃q=2*(1/2)=1.
b₅=b₄q=1*(1/2)=1/2.
S₂₋₅=4+2+1+1/2=7¹/₂=7,5.
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Автор:
blair - 5 лет назад
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Даны стороны ВС и АС треугольника АВС и ∠А, противолежащий стороне ВС. Найдите другие углы и третью сторону: ВС=27 см, АС=9 см, ∠А=138°
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