Ответ: -2,25 ≤ k ≤ -2.
Объяснение: во вложениях.
[x²(x + 4) + 1 - 3x)] = [16*(x + 4) - 3x + 1]
x³ + 4x² + 1 - 3x = 16x + 64 - 3x + 1
ОДЗ: x+ 4 ≠ 0, x ≠ - 4
x³ + 4x² - 16x - 64 = 0
x²(x + 4) - 16(x + 4) = 0
(x + 4)(x² - 16) = 0
x + 4 = 0, x = - 4 не удовлетворяет ОДЗ
x² - 16 = 0
x² = 16
x₁ = - √16
x₁ = - 4 не удовлетворяет ОДЗ
x₂ = √16
x₂ = 4
Ответ: x = 4
<span>(6b-8)(8b+6)-8b(6b+8) =48b</span>²+36b-64b-48-48b²-64b=-92b-48
b=-3; -92·(-3)-48=276-48=228
ОДЗ : x > 0
+ - +
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x ∈ (2 ; + ∞)
+ - +
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x ∈ (0 ; 1)
Ответ : (0 ; 1) ∪ (2 , + ∞)
Январь - n
февраль - 1,1n
март - 1,2*1,1n = 1,32n
за три месяца = n + 1,1n + 1,32n = 3,42n