Answer: $5000
Explanation:
We can use the formula:
tip = rate × cost
where the rate is the percentage written as a decimal. In this case, the rate is 0.09 (9% expressed as a decimal), and the tip is $450. We want to find the cost of the manicure, which is represented by the variable b. So, the equation becomes:
450 = 0.09b
To solve for b, we can divide both sides of the equation by 0.09:
b = 450 ÷ 0.09
b = 5,000
Therefore, the cost of the manicure was $5,000.