Remember, [tex](a^{m})^{n} = a^{mn}[/tex]. Therefore, the answer is [tex](2^{-4}){5} \times (z^{-3}){5}[/tex], which is [tex]2^{-20} \times x^{-15}[/tex].
A number to a negative power is the reciprocal of the number ([tex]x^{-y} = \frac{1}{x^{y}}[/tex].
The correct answer is B.
