1. Lesson 9-5 Multiplication with the Addition /Subtraction Method Objective: To use multiplication with the addition or subtraction method to solve systems of linear equations.

2. Warm up 1. 8q + 12 r = 20 5q + 12 r = -1 2. a – 2b = 0 a + 2b = 12 3. 2.58d – 0.03e = 15 1.72d – 0.03e = 19.4

3. Solve by Addition/Subtraction with Multiplication 6x + y = 6 3x + 2y =9 – Adding or subtracting these won’t drop out one of the variables. – So- multiply one of the equations so that a variable will have the same coefficient as the variable in the other equation. – Then add or subtract.

4. Example 4x – 5y = 3 3x + 2y = - 15 (-3. -3)

5. Practice 4x – 2y =10 3x – y =12 (7,9) 5a + 3b = 43 -a + 7b = -1 (8,1) m + 2n = 6 -2m + 4n =28 (-4, 5)