Answer:
$2.89 = 0.85b
Explanation:
The original price is b, and b is 100% of the original price since 100% is the entire thing. Original price: 100%b.
The discount is 15%. That means after the discount, the price is the original price b minus 15% of b.
100%b - 15%b = 85%b = 0.85b
After taking off the 15% discount, the discounted price is 0.85b.
We are told that the discounted price is $2.89. That means that 0.85b must equal $2.89.
The equation is
0.85b = $2.89
Switch the sides to get
$2.89 = 0.85b