(5^2)^-8 / 5^-15

1. Simplify the numerator: (5^2)^-8 = 5^(2 * -8) = 5^-16.
2. Divide the terms: 5^-16 / 5^-15 = 5^(-16 - (-15)) = 5^(-16 + 15) = 5^-1.
3. Express the result: 5^-1 = 1/5.