Jace is buying cookies and brownies for a party. He needs at least 8 cookies and at least 4 brownies. A cookie costs $3 and a brownie costs $5. The most he can spend is $60. A.

Create a system of linear inequalities in two variables from the description. Define your variables.

Consider each of the following potential solutions. For each potential solution, determine whether it is a viable solution, a nonviable solution, or not a solution.(3 points)
viable solution nonviable solution not a solution
10 cookies and 5 brownies
8.5 cookies and 4 brownies
20 cookies and 0 brownies

1 answer

Let's define the variables and create the system of linear inequalities based on the problem description:

Variables:

  • Let \( x \) be the number of cookies Jace buys.
  • Let \( y \) be the number of brownies Jace buys.

Inequalities:

  1. Jace needs at least 8 cookies: \[ x \geq 8 \]
  2. Jace needs at least 4 brownies: \[ y \geq 4 \]
  3. Each cookie costs $3 and each brownie costs $5. Jace can spend a maximum of $60: \[ 3x + 5y \leq 60 \]

Thus, the system of inequalities is:

  1. \( x \geq 8 \)
  2. \( y \geq 4 \)
  3. \( 3x + 5y \leq 60 \)

Now, let's evaluate each potential solution:

  1. 10 cookies and 5 brownies: \[ x = 10, , y = 5 \]

    • Check the inequalities: \[ 10 \geq 8 \quad (\text{true}) \] \[ 5 \geq 4 \quad (\text{true}) \] \[ 3(10) + 5(5) = 30 + 25 = 55 \leq 60 \quad (\text{true}) \]
    • Conclusion: This is a viable solution.
  2. 8.5 cookies and 4 brownies: \[ x = 8.5, , y = 4 \]

    • Check the inequalities: \[ 8.5 \geq 8 \quad (\text{true}) \] \[ 4 \geq 4 \quad (\text{true}) \] \[ 3(8.5) + 5(4) = 25.5 + 20 = 45.5 \leq 60 \quad (\text{true}) \]
    • Conclusion: This is a viable solution.
  3. 20 cookies and 0 brownies: \[ x = 20, , y = 0 \]

    • Check the inequalities: \[ 20 \geq 8 \quad (\text{true}) \] \[ 0 \geq 4 \quad (\text{false}) \] \[ 3(20) + 5(0) = 60 + 0 = 60 \quad (\text{true}) \]
    • Conclusion: This is a nonviable solution due to failing the brownie requirement.

Summary of Solutions:

  • 10 cookies and 5 brownies: viable solution
  • 8.5 cookies and 4 brownies: viable solution
  • 20 cookies and 0 brownies: nonviable solution