1)
[tex]\displaystyle\left(8^{4}\right)^{\frac{3}{4}}=8^3=512[/tex]
2)
[tex]\displaystyle\left(\sqrt[4]{81}\right)^{3}=3^3=27[/tex]
3)
[tex]\displaystyle 1296^{\frac{3}{4}}=6^3=216[/tex]
4)
[tex]\displaystyle 16^{\frac{3}{4}}=2^3=8[/tex]
5)
[tex]\displaystyle\left(\sqrt[4]{2401}\right)^{3}=7^3=343[/tex]
6)
[tex]\displaystyle \left(6561^{\frac{1}{4}}\right)^{3}=9^3=729[/tex]