Final answer:
By setting up a system of linear equations and using the elimination method, we find that the cost of each bag of chips is $2.
Step-by-step explanation:
The student's question involves solving a system of linear equations to determine the cost of each bag of chips and each package of cookies. We can set up two equations based on the information given: one representing the student's purchase and one for the best friend's purchase. Let ‘c’ be the cost of a bag of chips and ‘d’ be the cost of a package of cookies.
Equation 1: 7c + 3d = $17 (the student's purchase)
Equation 2: 3c + 1d = $7 (the best friend's purchase)
To find the cost of a bag of chips, we can solve this system using either substitution or elimination method. In this case, the elimination method can be applied effectively.
Multiplying the second equation by 3 gives us a new equation:
Equation 3: 9c + 3d = $21
Now subtracting Equation 1 from Equation 3, we get:
2c = $4
Dividing both sides of the equation by 2, we find that:
c = $2
Thus, each bag of chips costs $2.