For this case we have by definition of properties of powers that:
To multiply powers of the same base, the same base is placed and the exponents are added. Also:
[tex]a ^ {- 1} = \frac {1} {a ^ 1} = \frac {1} {a}[/tex]
Now, applying the above properties, we can rewrite the given expression as:
[tex]3 ^ {-3-5} = 3 ^ {- 8} = \frac {1} {3 ^ 8}[/tex]
ANswer:
[tex]\frac {1} {3 ^ 8}[/tex]
