1. Graph y = 2x – 3 2. Graph y = ½ x Graph 6x + 3y = 9 4. Graph x + 2y = -1

Solve the following Equations 1. 5x + (3x – 5) = x + 5 = x

CCGPS Coordinate Algebra Day 15 ( ) UNIT QUESTION: How do I justify and solve the solution to a system of equations or ine5ualities? Standard: MCC9-12.A.REI.1, 3, 5, 6, and 12 Today’s Question: Does multiplying an equation by a constant change the solution to a system of equations? Standard: MCC9-12.A.REI.5



Solution: (-1, 3) Does the solution still work if you multiply one or both of the equations by a number like 2 or -2?

1. Arrange the equations with like terms in columns 2. Multiply, if necessary, to create opposite coefficients for one variable. 3. Add/Subtract the equations. 4. Substitute the value to solve for the other variable. 5. Write your answer as an ordered pair. 6. Check your answer.

4x + 3y = 16 2x – 3y = 8

3x + 2y = 7 -3x + 4y = 5

2x – 3y = -2 -4x + 5y = 2

5x + 2y = 7 -4x + y = –16

2x + 3y = 1 4x – 2y = 10

Add/Subtract Use elimination to solve each system of equations x – 5y = m – 4n = a + b = 1 6x – 7y = -20 3m + 2n = -2 a + b = x – 4y = x – 3y = x – 2y = 6 -3x + y = 2 2x – 3y = 16 x + y = 3 7.2a – 3b = x + 2y = x – y = 6 2a + 2b = 7 4x + 4y = 10 5x + 2y = 3

Multiply Use elimination to solve each system of equations. 1.2x + 3y = m + 3n = a - b = 2 x + 2y = 5 -m + 2n = 5 a + 2b = 3 4.4x + 5y = x – 3y = x – 4y = -4 6x - 7y = -20 2x – y = 10 x + 3y = x – y = a – 3b = x + 2y = 5 5x + 2y = 8 2a + 2b = 3 4x - 4y = 10

Practice Worksheet Work book: Pages 115 and 116 #1-14, not #6