Question

x^2-5=(x+5)(2x-1)
Помогите пожалуйста ,срочно

Answer 1

x^2 - 5 = 2x^2 - x + 10x - 5

x^2 - 2x^2 - 9x = 0

- x^2 - 9x = 0

x^2 + 9x = 0

x (x + 9) = 0

1) x = 0;

2) x + 9 = 0 ==> x = - 9

Ответ

- 9; 0

Answer 2

x² - 5 = (x + 5) * (2x - 1)

x² - 5 = 2x² - x + 10x - 5

x² = 2x² - x + 10x

x² = 2x² + 9x

x² - 2x² - 9x = 0

-x ² - 9x = 0

$x = \frac{ - ( - 9)± \sqrt{( - 9) {}^{2} - 4} *( - 1) *0}{2 *( - 1)} \\ \\ x = \frac{9 ± \sqrt{( - 9) {}^{2} } - 0 }{ - 2} \\ \\ x = \frac{9 ± \sqrt{( - 9) {}^{2} } }{ - 2} \\ \\ x = \frac{9 ± 9}{ - 2} \\ \\ x = - \frac{9 ± 9}{2} \\ \\ \\ x = - \frac{9 + 9}{2} \\ \\ x = - \frac{9 - 9}{2} \\ \\ x = - 9 \\ x = 0$

ответ: x₁ = -9 x₂ = 0