Sure, I can help you with that.
Let's use the simple interest formula:
Simple Interest (SI) = Principal * Interest Rate * Time
We are given the following information:
* SI = $525
* R = 5% = 0.05
* T = 1 year
We need to find the principal, which is denoted by P.
P = SI / R * T
P = 525 / 0.05 * 1
P = $10,500
Therefore, Miguel borrowed $10,500.
I hope this helps! Let me know if you have any other questions.
Is there anything else I can help you with?