Final answer:
To calculate the total price before the discount was applied, subtract the discount amount from the subtotal.
Step-by-step explanation:
To calculate the total price before the discount was applied, you would need to subtract the discount amount from the subtotal.
Option d) Subtract $15% from $36.74 is the correct operation to use in this case.
So, the total price before the discount was applied would be $36.74 - $5.51 (which is 15% of $36.74) = $31.23.