Start by decomposing the number inside the root into primes
Then group the terms into cubes if possible
[tex]\begin{gathered} 80=2\cdot2\cdot2\cdot2\cdot5 \\ 80=2^3\cdot2\cdot5 \\ 80=10\cdot2^3 \end{gathered}[/tex]
rewrite the root
[tex]\sqrt[3]{80}=\sqrt[3]{10\cdot2^3}[/tex]
then cancel the terms that are cubes and bring them out of the root
[tex]\sqrt[3]{80}=2\sqrt[3]{10}[/tex]
