Ответ:

Объяснение:

1) x^3 - 4x = 0
x(x^2 - 4)=0
x(x - 2)(x + 2) = 0
x = 0, x = 2, x = -2

2)x^4 - x^2 = 0
x^2(x^2 - 1) = 0
x^2(x-1)(x + 1)= 0
x = 0, x = 1, x = -1

5) x^3 - 10x^2 + 25x = 0
x(x^2 - 10x + 25) = 0
D = 100 - 25 * 4 = 0
x = 10/2 = 5
x(x-5)^2 = 0
x = 0, x = 5

6) x^3 + 2x^2 - 9x - 18 = 0
x^2(x + 2) - 9(x + 2)= 0
(x+2)(x^2 - 9) = 0
(x + 2)(x - 3)(x+3) = 0
x = -2, x = 3, x = -3