Answer:
$10
Step-by-step explanation:
The price of the item before tax is 100% of its price since 100% means the entire thing.
When you add a 15% tax, the total price (including tax) is now 115% of the original price.
The original price is unknown, so we call it x.
115% of x is $11.50
115% * x = 11.50
1.15x = 11.5
x = 10
