Question

Решите уравнения:
А) x^3+5x^2-25x-125=0
Б) x^3+7x^2-49x-343=0

Answer 1

A)
x³ + 5x² - 25x - 125 = 0
x²(x + 5) - 25(x + 5) = 0
(x² - 25)(x + 5) = 0
(x - 5)(x + 5)² = 0
x =  ±5
Ответ: -5; 5

Б)
x³ + 7x² - 49x - 343 = 0
x²(x + 7) - 49(x + 7) = 0
(x² - 49)(x + 7) = 0
(x - 7)(x + 7)² = 0
x = ±7
Ответ: -7; 7