a) $$(2xy^4)^2 = 2^2 \cdot x^2 \cdot (y^4)^2 = 4x^2y^8$$
б) $$(-3x^4y^2)^3 = (-3)^3 \cdot (x^4)^3 \cdot (y^2)^3 = -27x^{12}y^6$$
в) $$(0,1a^2b^3c^5)^2 = (0,1)^2 \cdot (a^2)^2 \cdot (b^3)^2 \cdot (c^5)^2 = 0,01a^4b^6c^{10}$$
г) $$81x^{11}z^5: (-27x^9z^5) = \frac{81x^{11}z^5}{-27x^9z^5} = \frac{81}{-27} \cdot \frac{x^{11}}{x^9} \cdot \frac{z^5}{z^5} = -3x^2$$
д) $$(\frac{1}{3}y^2x)^3 \cdot (3x^2y)^2 = (\frac{1}{3})^3 \cdot (y^2)^3 \cdot x^3 \cdot 3^2 \cdot (x^2)^2 \cdot y^2 = \frac{1}{27}y^6x^3 \cdot 9x^4y^2 = \frac{9}{27} \cdot x^3 \cdot x^4 \cdot y^6 \cdot y^2 = \frac{1}{3}x^7y^8$$