1. Solving Systems of Equations by Elimination

2. Standard and Objective A.REI.5 Prove that, given a system of two equations in two variables, replacing one equation by the sum of that equation and a multiple of the other produces a system with the same solutions. SWBAT solve systems of equations by elimination

3. The last method of solving systems of equations is the ELIMINATION method. This method uses the idea of additive inverses to eliminate a VARIABLE.

4. Quick Check! Find the additive inverse 1.42. –x 3. 5x4. 8y

5. Steps Step 1: Are any terms additive inverses? If yes, add the two equations If no, multiply a constant to one or both equations so that there are. (At least one variable should cancel out) Step 2: Solve for the remaining variable. Step 3: Substitute the value into one of the original equations. Step 4: Solve for the remaining variable. Step 5: check your solution.

6. Example 1

7. Example 2

8. Guided Practice

9. Independent Practice

10. Homework Due next class!