Ответ:

  1. а) \((3x^6y^3)^4\cdot\left(-\frac{1}{81}xy^2\right)=81x^{24}y^{12}\cdot\left(-\frac{1}{81}xy^2\right)=-x^{25}y^{14}\).
  2. б) \(\left(\frac{2}{3}x^2y^3\right)^3\cdot(-9x^4)^2=\frac{8}{27}x^6y^9\cdot81x^8=24x^{14}y^9\).
  3. в) \((3a^2)^2\cdot(-6a^3)=9a^4\cdot(-6a^3)=-54a^7\).
  4. г) \(\left(\frac{1}{8}x^2y^3\right)\cdot(2x^6y)^4=\frac{1}{8}x^2y^3\cdot16x^{24}y^4=2x^{26}y^7\).