1. ©Evergreen Public Schools 2011 1 Learning Target I can write and solve problems with two variables algebraically by using the elimination method. What is the elimination method?

2. ©Evergreen Public Schools 2011 2 LaunchLaunch Simone work on her Science Fair project. She bought 5 markers and 2 highlighters on Monday for $8.23 before tax. Wednesday she spent $5.65 on 3 more markers and 2 more highlighters. Write and solve a system of equations to find how much Simone paid for one marker.

3. ©Evergreen Public Schools 2011 3 ExploreExplore

4. 4 Solve for x. What would this system of equations have to look like so you could use the elimination method? How could you get the system to look that way? More Elimination Method

5. ©Evergreen Public Schools 2011 5 Solve for x. We can multiply the top equation by 5 More Elimination Method

6. ©Evergreen Public Schools 2011 6 What do you have to do the one or both equations to solve with the elimination method? More Elimination Method

7. ©Evergreen Public Schools 2011 7 Make sure equations are in standard form. Decide whether the x or y coefficients would be easiest to eliminate by adding the two equations together. Decide what to multiply each equation by so that when you add the two, the variable will be eliminated. Work though this one in your notes pages More Elimination Method

8. ©Evergreen Public Schools 2011 8 4 x – 2 y = -4 2 x + 3 y = 10 4 x – 2 y = -4 -2 (2 x + 3 y = 10) 4 x – 2 y = -4 + -4 x – 6 y = -20 0 x – 8 y = -24 y = 3 Solve for x : 2 x + 3 y = 10 2 x + 3(3) = 10 2 x + 9 = 10 2 x = 1 x = ½

9. ©Evergreen Public Schools 2011 9 Check the solution in each equation: x = ½ y = 3 2 x + 3 y = 10 2 (½) + 3(3) = 10 1 + 9 = 10 10 = 10 4 x – 2 y = -4 4(½) – 2(3) = -4 2 – 6 = -4 -4 = -4

10. ©Evergreen Public Schools 2011 10 PracticePractice Solve the system of equations 1) 5 x + y = 9 2) – 4 x + 9 y = 18 10 x – 7 y = – 18 x + 3 y = 27 3) – 7 x + y = – 19 4) 3 x – 7 y = 45 – 2 x + 3 y = – 19 – 9 x + 5 y = – 87

11. ©Evergreen Public Schools 2011 11 Team Practice The manager for the professional soccer team, the Portland Timbers, wants to have a promotional game where she gives away sports bags and caps to fans. She can buy bags for $12 and caps for $15. The total budget for the promotion is $53,100 She plans to give the first 4000 fans either a bag or a cap, but not both. How many bags and caps can she give away? Work though this one in your notes pages

12. ©Evergreen Public Schools 2011 12 Share variables and equations Share how many bags and caps can be given away Team Practice

13. ©Evergreen Public Schools 2011 13 DebriefDebrief In your notes pages: Summarize how to solve systems of equations with the elimination method.

14. ©Evergreen Public Schools 2011 14 5 3 1 2 4 Learning Target Did you hit the target? I can write and solve problems with two variables algebraically by using the elimination method. Rate your understanding of the target from 1 to 5. 5 is a bullseye!

15. ©Evergreen Public Schools 2011 15 Finish “Elimination Method Practice Day 2” Practice