1. ALGEBRA 1 CC Creating Equations and Graphing & Labeling Scales

2. Example 1 a) A gym charges $30 per month after an initial membership fee. A member has paid a total of $250 after 6 months. Write an equation that gives the total cost of a gym membership as a function of the length of membership (in months). b) Find the total cost after 10 months.

3. c) Graph the equation from part (a).

4. Example 2 The fifth grade classes at Walnut Grove are going on a field trip. They can ride in small and large vans. A small van holds 8 people and a large van holds 12 people. They could fill 15 small vans and 2 large vans. a) Write an equation in standard form that models the possible combinations of small vans and large vans that the classes could fill

5. b) Graph the equation from part (a).

6. c) List several possible combinations.

7. Example 3 From 1990 to 2001, the number of airports in the United States increased at a relatively constant rate of 175 airports per year. There were 19,306 airports in the United States in 2001. a) How many U.S. airports were there in 1990? b) Write an equation that gives the number of U.S. airports as a function of the number of years since 1990.

8. c) Graph the equation from part (b). d) Find the year in which the number of U.S. airports reached 19,200.