To set up the system of equations based on the purchases of Sara, Jennifer, and Katrina, we need to use the following variables:
- Let \( x \) be the price of a bag of chips.
- Let \( y \) be the price of a soda.
- Let \( z \) be the price of a candy.
We can create the following equations from the information given:
-
Sara's purchases:
Sara bought 4 bags of chips, 4 sodas, and 6 candies, totaling $21.00.
This can be expressed as:
\[ 4x + 4y + 6z = 21 \] -
Jennifer's purchases:
Jennifer bought 3 bags of chips, 2 sodas, and 10 candies, totaling $20.88.
This can be expressed as:
\[ 3x + 2y + 10z = 20.88 \] -
Katrina's purchases:
Katrina bought 2 bags of chips, 3 sodas, and 4 candies, totaling $13.17.
This can be expressed as:
\[ 2x + 3y + 4z = 13.17 \]
Now we have the following system of equations:
- \( 4x + 4y + 6z = 21 \)
- \( 3x + 2y + 10z = 20.88 \)
- \( 2x + 3y + 4z = 13.17 \)
From the options provided, the equation that is part of the system is:
- 4x + 4y + 6z = 21
This is the correct equation that corresponds to Sara's purchases.
So the answer is: \[ \boxed{4x + 4y + 6z = 21} \]