which expression is equivalent to (look at picture)

For this case we must indicate an expression equivalent to:
[tex](2 ^ 3) ^ {-5}[/tex]
By definition of power properties we have to:
[tex](a ^ n) ^ m = a ^ {n * m}[/tex]
We also have to:
[tex]a ^ {- 1} = \frac {1} {a ^ 1} = \frac {1} {a}[/tex]
Rewriting the expression we have:
[tex](2 ^ 3) ^ {-5} = 2 ^ {-15} = \frac {1} {2 ^ {15}}[/tex]
Answer:
Option A