One engaging realworld application of linear equations for Year 9 students could be calculating the cost of a school trip.
Task: Your school is planning a trip to a local amusement park. The cost of the trip includes the entrance fee and transportation. The entrance fee for each student is $20, and the transportation cost is $200 for the entire group.

Write a linear equation to represent the total cost (C) of the trip based on the number of students (S) attending the trip.

Solve the equation to find the total cost of the trip for different numbers of students attending.

Create a table and a graph to represent the relationship between the number of students and the total cost of the trip.

Use the equation to calculate the total cost for a specific number of students, such as 30 or 50.

Discuss how the equation can be used to predict the total cost for any number of students attending the trip.
Extension: 6. Introduce a variable for the cost of food per student (F). Write a new equation to represent the total cost of the trip, including the cost of food.

Solve the new equation for different numbers of students and different food costs.

Compare the total cost of the trip with and without the cost of food. Discuss how the cost of food affects the total cost and how it can be minimized.
This task allows students to apply their knowledge of linear equations to a realworld scenario, while also practicing graphing, creating tables, and making predictions. It also encourages critical thinking by introducing the concept of minimizing costs by adjusting variables.