Question

Помогите пожалуйста решить уравнение:
2x^3+x^2-8x-7=0

Answer 1

Ответ:

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Answer 2

2x³ + x² - 8x - 7 = 0

2x³ + 2x² - x² - 8x - 7 = 0

(2x³ + 2x²) - (x² + 8x + 7) = 0

2x²(x + 1) - (x + 1)(x + 7) = 0

(x + 1)(2x² - x - 7) = 0

x + 1 = 0

x₁ = - 1

2x² - x - 7 = 0

D = (-1)² - 4 * 2 * (- 7) = 1 + 56 = 57

$x_{2}=\frac{1-\sqrt{57}}{4} \\\\x_{3}=\frac{1+\sqrt{57} }{4}$