Question

Решите уравнение х^3-2х^2-15х=0

Answer 1

x³ - 2x² - 15x = 0

x•(x² - 2x - 15) = 0

x₁ = 0

или

x² - 2x - 15 = 0

D = (-2)² - 4•1•(-15) = 4 + 60 = 64 = 8²

x₂ = (2 - 8)/2 = - 6/2 = - 3

x₃ = (2 + 8)/2 = 10/2 = 5

ОТВЕТ: - 3 ; 0 ; 5