1. Section 7 – 3 Solving Systems Using Elimination Objectives: To solve systems by adding or subtracting To multiply first when solving systems

2. Elimination Method: Add or subtract equations to eliminate a variable. REMEMBER:Opposites Cancel! - 5 + 5 = 05x + -5x = 0

3. Example 1Adding/Subtracting Equations A)Solve using elimination.5x – 6y = -32 3x + 6y = 48

4. B)Solve using elimination.6x – 3y = 3 -6x + 5y = 3

5. C)Solve using elimination.2x – 3y = 61 2x + y = - 7

6. Homework Answers: 1)(6, -6)2)(7, -1) 3)(10, -1)4)(-1, -1) 5)(-1, 3)

7. WARM UP Solve using elimination.2x + 18y = - 9 4x + 18y = -27

8. Section 7 – 3 Continued Objectives: To multiply first when solving systems

9. Example 2Multiplying One Equation A)Solve by the elimination method. 2x + 5y = - 22 10x + 3y = 22

10. B)Solve by the elimination method. -2x + 15y = -32 7x – 5y = 17

11. C)Solve by the elimination method. -6x + 5y = 4 3x + 4y = 11

12. D)Solve by the elimination method. 3x + 6y = -6 -5x – 2y = -14

13. Section 7 – 3 Continued (Day 3) Objectives: To multiply first when solving systems

14. Example 3 Multiplying Both Equations A)Solve by the elimination method. 4x + 2y = 14 7x – 3y = - 8

15. B)Solve by the elimination method. 15x + 3y = 9 10x + 7y = - 4

16. C)Solve by the elimination method. 3x+ 5y = 10 5x + 7y = 10

17. D)Solve by the elimination method. 7p + 5q = 2 8p – 9q = 17

18. Example 4 Word Problems A)Your community center sells a total of 292 tickets for a basketball game. An adult ticket costs $3. A student ticket costs $1. The sponsors collect $470 in ticket sales. Write and solve a system to find the number of each type of ticket sold.

19. B)The freshman class sells a total of 64 tickets to a play. A student ticket costs $1 and an adult ticket costs $2.50. Your class collects $109 in total ticket sales. How many adult tickets did you sell? How many student tickets did you sell?

20. C)Suppose the Junior Class sells gift wrap for $4 per package and greeting cards for $10 per package. Your class sells 205 packages in all and receives a total of $1084. Find the number of packages of gift wrap and the number of packages of greeting cards sold.

21. D)Suppose the band sells bags of popcorn for $5 per bag and bags of mixed nuts for $8 per bag. The band sells a total of 240 bags and receives a total of $1614. Find the number of bags of popcorn and the number of bags of mixed nuts sold.