1. Graphing Linear Inequalities in Two Variables Section 2.8

2. Which of the following ordered pairs is a solution of 2x + 5y > 9 ? A)(–4, –1) B)(–2, 3) C)(2, –4) D)(6, –1) Review 7/20/2012 9:41 PM 2.8: Graph Linear Inequalities in Two Variables 2

3. A.Draw the graph either applying slope–intercept or quick graph form 1.When using “cover–up,” if there is a negative coefficient in the y, flip the direction of the graph B.Determine what the sign is and graph the line 1.Dotted Line: Greater, Less, or not–equal to 2.Solid Line: Greater then OR equal to, Less than OR equal to, Equal to C.Shade above or below the line by looking at inequality Steps in Graphing 7/20/2012 9:41 PM 2.8: Graph Linear Inequalities in Two Variables 3

4. Greater Than Steps in Graphing 7/20/2012 9:41 PM 2.8: Graph Linear Inequalities in Two Variables 4

5. Less Than Steps in Graphing 7/20/2012 9:41 PM 2.8: Graph Linear Inequalities in Two Variables 5

6. Graph 2x + 3y < 6 Example 1 7/20/2012 9:41 PM 2.8: Graph Linear Inequalities in Two Variables 6 Graph, as if, it was an equality. (3, 0) and (0, 2) OR

7. Graph –4x – 2y > 8 Example 2 7/20/2012 9:41 PM 2.8: Graph Linear Inequalities in Two Variables 7 (–2, 0) and (0, –4) OR

8. Graph –4x – 2y > 8 Example 2 Calculator 7/20/2012 9:41 PM 2.8: Graph Linear Inequalities in Two Variables 8 Must be in slope–intercept form Go to Y= in graphing calculator

9. Graph –4x – 2y > 8 Example 2 Calculator 7/20/2012 9:41 PM 2.8: Graph Linear Inequalities in Two Variables 9

10. Graph y > 4 Example 3 7/20/2012 9:41 PM 2.8: Graph Linear Inequalities in Two Variables 10

11. Graph x < 7 Example 4 7/20/2012 9:41 PM 2.8: Graph Linear Inequalities in Two Variables 11

12. Graph 3 > 3/2y Your Turn 7/20/2012 9:41 PM 2.8: Graph Linear Inequalities in Two Variables 12 y < 2

13. Graph 2/3 (2x – y) < 2 Example 5 7/20/2012 9:41 PM 2.8: Graph Linear Inequalities in Two Variables 13 y > 2x – 3

14. You have two part–time summer jobs, one that pays $9 and hour and another that pays $12 an hour. You would like to earn at least $240 a week. Write an inequality describing the possible amounts of times you can schedule at each jobs. Graph the inequality. Each space is worth 5. Example 6 7/20/2012 9:41 PM 2.8: Graph Linear Inequalities in Two Variables 14 $12 an hour job (every 5) $9 an hour job (every 5)

15. A pizza place has 4800 ounces (300 pounds) of dough. A small pizza uses 12 ounces of dough and a large pizza uses 18 ounces of dough. Write and graph an inequality describing the possible numbers of small and large pizzas that can be made. Each space is worth 50. Your Turn 7/20/2012 9:41 PM 2.8: Graph Linear Inequalities in Two Variables 15 Large Pizzas (per 50) Small Pizzas (per 50)

16. Page 135 3–27 odd, 43–47 odd Assignment 7/20/2012 9:41 PM 2.8: Graph Linear Inequalities in Two Variables 16