Answer:
The Money supply will decrease by $4,500
Step-by-step explanation:
What will be the maximum impact on money supply today as a result of your action is that the Money supply will decrease by $4,500.
Since we assumed that you have $10,000 in your account in which you withdraw $500 cash from your account and hide it under your pillow for future use, therefore based this scenario or actions carried by you it means that your bank have fewer or lesser funds available to make loans which means the decrease will tend to affect the money supply.
Hence, you can easily calculate the effect by using the simple money multiplier.