1. My Contract is Up… Who has the best deal? Graphing Linear Equations

2. Lesson Objectives How to use linear equations to describe and interpret real-life situations How to graph linear equations to visualize linear relationships

3. Problem AT & T does not have an initial monthly charge for its GoPhone, but it charges 75 cents for every minute. Your mom has just taken your cell phone because you had bad grades 2 nd quarter, and you have decided to purchase your own phone. Below is the information you gathered regarding the plans you are considering. SPRINT has an initial monthly charge of $25 for providing their services and charges 30 cents for every minute. VERIZON charges $55 per month and 10 cents for every minute. Note: No more free minutes included in plans!

4. Task You decided to look deeply into these plans before making a decision. You are to create the following: Equations that represent each of your options A graphical representation of the information you have gathered

5. Group Activity  Come up with the equation that represents each cell phone plan (Make sure everyone in your group understands what each element in the equation represents)  Graph all 3 functions on one piece of graph paper. Make sure you label all parts of the graph, use 3 different colors to represent each company, and create a key for your graph.  Looking at your graph, you will answer the questions given on the worksheet.

6. Individual Assessment If you talked an average of less than 50 minutes a month, which company would provide the best rate? Which company would you choose if you talked an average of 100 minutes per month? Compare the prices for all 3 companies at 100 minutes. How much cheaper is the best plan when compared to each of the other two plans? Which company would provide the best rate if: a) you talked an average of 200 minutes per month? b) you talked an average of 1000 minutes per month? At about how minutes would the rate be the same for SPRINT and VERIZON? Which company’s rate increases the fastest? How do you know? Which company’s rate stays closest to the starting rate? Which plan would be best for you? How did you choose?

7. Resources Writing Linear Equations Graphing Linear Equations Solving Systems of Equations Graphically