б) $$(-\frac{1}{3}ab^4c^2)^3 = (-\frac{1}{3})^3 \cdot a^3 \cdot (b^4)^3 \cdot (c^2)^3 = -\frac{1}{27} a^3 b^{12} c^6 $$
Ответ: $$\-\frac{1}{27} a^3 b^{12} c^6$$