źródło:
3\sqrt[3]{81\sqrt3}=3*81^{\frac{1}{3}}*(3^{\frac{1}{2}})^{\frac{1}{3}}=3*(3^4)^{\frac{1}{3}}*3^{\frac{1}{6}}=3^{1+\frac{4}{3}+\frac{1}{6}}=3^{\frac{6+8+1}{6}}=3^{\frac{15}{6}}=3^{\frac{5}{2}}