Cozy Closet children's store is having its annual winter sale, during which every item in the store is marked down. Pajama sets sell for [tex]$7[/tex] less than the full price. Mr. Dorsey purchases 3 matching pajama sets, one for each of his children, and pays a total of [tex]$57[/tex].

Which equation can you use to find how much money, [tex]f[/tex], each pajama set costs at full price?

A. [tex]7f - 3 = 57[/tex]

B. [tex]3(f - 7) = 57[/tex]

C. [tex]3f - 7 = 57[/tex]

D. [tex]7(f - 3) = 57[/tex]

Certainly! Let's go through the problem step-by-step to understand how to find the equation that represents the full price of each pajama set, [tex]$ f $[/tex].

1. Identify Variables:
- Let [tex]$ f $[/tex] represent the full price of one pajama set.

2. Understand the Sale Reduction:
- The sale reduces the price of each pajama set by [tex]$7. Therefore, during the sale, the cost of each pajama set is $ f - 7 $.

3. Total Purchase Cost:
- Mr. Dorsey buys 3 pajama sets during the sale. Thus, the total cost he pays is $[/tex]57.

4. Set Up the Equation:
- To find the total amount Mr. Dorsey spent, we multiply the sale price of one pajama set by the number of pajama sets purchased:
[tex]\[
3 \times (f - 7)
\][/tex]
- We know this amount equals $57. Therefore, our equation is:
[tex]\[
3 \times (f - 7) = 57
\][/tex]

This equation helps us determine the full price, [tex]$ f $[/tex], of one pajama set. The correct equation you can use to find [tex]$ f $[/tex] is:

[tex]\[ 3(f - 7) = 57 \][/tex]