Question

Помогите: 6x^3+21x^2+9x=0

Answer 1

6x³ + 21x² + 9x = 0
3x(2x² + 7x + 3) = 0
3x(2x² + 6x + x + 3) = 0
3x[2x(x + 3) + (x + 3)] = 0
3x(2x + 1)(x + 3) = 0
3x = 0   или   2x + 1 = 0    или   x + 3 = 0
x = -3; -0,5; 0

Ответ: x = -3; -0,5; 0.