You have the expression
[tex]n^3=n^{?}\cdot n^{-3}[/tex]
and want to find ?.
First, note the property
[tex]n^m\cdot n^k=n^{m+k}.[/tex]
Using this property, you can write
[tex]n^{?}\cdot n^{-3}=n^{?+(-3)}=n^{?-3}.[/tex]
If
[tex]n^3=n^{?-3},[/tex]
then
[tex]3=?-3,\\ \\?-3=3,\\ \\?=3+3,\\ \\?=6.[/tex]
Answer: 6.
