Explanation:
The rule used is [tex]\left(\frac{a}{b}\right)^{-c} = \left(\frac{b}{a}\right)^{c}[/tex]
That rule says to go from a negative exponent to a positive exponent, we apply the reciprocal of the fraction.
So,
[tex]\left(\frac{1}{3}\right)^{-5} = \left(\frac{3}{1}\right)^{5} = 3^5[/tex]