I think that you multiply the 2 outside the bracket with the exponent if 5 inside. So (5^5)^2 becomes 5^10. This is because when an exponent is raised to an exponent, they are multiplied. Then 5^10/5^3 is 5^7 because when dividing exponentes you subtract the numbers. You can double check in your calculator. Also this might be wrong but idk.