Ответ:

  1. \(\sqrt[3]{a}\cdot\sqrt[6]{a}=a^{1/3+1/6}=a^{1/2}=\sqrt{0.09}=0.3\).
  2. \(\sqrt b:\sqrt[6]{b}=b^{1/2-1/6}=b^{1/3}=\sqrt[3]{27}=3\).
  3. \(\frac{\sqrt b\cdot\sqrt[3]{b^2}}{\sqrt[6]{b}}=b^{1/2+2/3-1/6}=b=1.3\).
  4. \(\sqrt[3]{a}\cdot\sqrt[4]{a}\cdot\sqrt[12]{a^5}=a^{1/3+1/4+5/12}=a=2.7\).

Ответ: 1) 0.3; 2) 3; 3) 1.3; 4) 2.7.