We have:
[tex]4*\sqrt[3]{81}[/tex]
and we know that [tex]81=3^4[/tex], don't we?
therefore Let's replace it.
[tex]4*\sqrt[3]{3^4}[/tex]
and we can write this value like this [tex]3^4=3^3*3^1[/tex]
them, let's replace
[tex]4*\sqrt[3]{3^3*3^1}[/tex]
we can take out [tex]3^3[/tex], them we obtain
[tex]4*3*\sqrt[3]{3^1}[/tex]
[tex]\boxed{\boxed{4*\sqrt[3]{81}\equiv12*\sqrt[3]{3}}}[/tex]
