Question

x² + 2x - 8 =0 помогите​

Answer 1

Пошаговое объяснение:

$x^2 + 2x - 8 = 0\\ D = b^2 - 4ac\\ D = 2^2 - 4*1*(-8) = 4 + 32 = 36\\ x_{12} = \frac{-b \pm \sqrt{D}}{2a} = \frac{-2 \pm 6}{2}\\\\ x_1 = \frac{-2 + 6}{2} = \frac{4}{2} = 2\\ x_2 = \frac{-2-6}{2} = \frac{-8}{2} = -4$

Ответ: x1 = -4; x2 = 2