Lesson 7-5

1. Lesson 7-5 Graphing Systems of Inequalities

2. To solve a system of inequalities, you need to find the ordered pairs that satisfy all the inequalities involved. One way to do this is to graph the inequalities on the same coordinate plane. The solution set is represented by the intersection, or overlap, of the graphs.

3. x o y Ex. 1 Multiply one equation to Eliminate Solve the system of inequalities by graphing. y < -x + 1 Y ≤ 2x + 3

4. x o y Multiply one equation to Eliminate Solve the system of inequalities by graphing. y < 2x + 2 y  -x -3

5. x o y Ex. 2 No Solution Solve the system of inequalities by graphing. x - y < -1 x - y > 3

6. x o y No Solution Solve the system of inequalities by graphing. y  -3x + 1 y  -3x -2

7. 1000 800 600 Math Score 400 200 200 400 600 800 1000 Verbal Score Ex. 3 Use a System of Inequalities to Solve a Problem The middle 50% of first-year students attending Florida State University score between 520 and 620, inclusive, on the verbal portion of the SAT and between 530 and 630, inclusive, on the math portion. Graph the scores that a student would need to be in the middle 50% of the FSU freshmen. Verbal between 520 and 620 Math between 530 and 630 520  v  620 530  m  630

8. 20 16 12 Library 8 4 4 8 12 16 20 Mowing Use a System of Inequalities to Solve a Problem Jamail mows grass after school but his job pays only $3 per hour. He has been offered another job as a library assistant for $6 per hour. Because of school, his parents allow him to work at most 15 hours per week. How many hours can Jamail mow grass and work in the library and still make at least $60 per week? G + L = 15 3G + 6L = 60