1. Solving a System of Equations by ELIMINATION

2. Elimination Solving systems by Elimination: 1.Line up like terms in standard form x + y = # (you may have to use inverse operations) 2.Look at coefficients for something to cancel / eliminate (you may have to multiply) 3.Add equations together 4. Solve for the remaining variable. 5. Substitute back into original equation

3. -2(3x + 2y = -6) -6x – 4x = 12 3(2x + 5y = 7) 6x + 15y = 21 11y = 33 y = 3 3x + 2y = -6 2x + 5y = 7 3x + 2(3) = -6 3x + 6 = -6 -6 -6 3x = -12 3 x = -4 The solution to the system is (-4,3)

4. 4x + 3y = 5 2x – 3y = 7 Line up like terms (you may have to use inverse operations) Look for something to cancel (you may have to multiply) Add equations together Substitute back into original equation Check!

5. 2x + y = 9 -x + 4y = 0

6. 6x – 3y = -3 -12x + 3y = -3

7. 3x – 3y = -15 -4x + 2y = 4

8. x + y = 2 x – y =0

9. Review What are the steps for solving a system of equations by elimination?