389. 1) (2x²-5x+3)·(-4x); 2) (x²-x+1)·(-2x); 3) (-4a³-6a-8)·(-⅓ a); 4) (-3m²+9m - 12)·(-⅓ m).

Решение:

1. \( (2x^2-5x+3)(-4x) = -8x^3+20x^2-12x \)
2. \( (x^2-x+1)(-2x) = -2x^3+2x^2-2x \)
3. \( (-4a^3-6a-8)(-\frac{1}{3} a) = \frac{4}{3}a^4 + 2a^2 + \frac{8}{3}a \)
4. \( (-3m^2+9m-12)(-\frac{1}{3} m) = m^3 - 3m^2 + 4m \)

Ответ: 1) \( -8x^3+20x^2-12x \); 2) \( -2x^3+2x^2-2x \); 3) \( \frac{4}{3}a^4 + 2a^2 + \frac{8}{3}a \); 4) \( m^3 - 3m^2 + 4m \).