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1. Graph y = 2x – 3
2. Graph y = ½ x + 2
3. Graph 6x + 3y = 9
4. Graph x + 2y = -1
Solve the following Equations
1. 5x + (3x – 5) = -25
2. 4x + 5 = -17 + 2x
CCGPS Coordinate Algebra
Day 15 (8-22-14)
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


2 x  2 y  8
2 x  2y  4
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.
2.
3.
4.
5.
6.
Arrange the equations with like terms in
columns
Multiply, if necessary, to create opposite
coefficients for one variable.
Add/Subtract the equations.
Substitute the value to solve for the other
variable.
Write your answer as an ordered pair.
Check your answer.
2 x  2 y  8
2 x  2y  4
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.
1. -6x – 5y = -4
2. 3m – 4n = -14
3. 3a + b = 1
6x – 7y = -20
3m + 2n = -2
a+b=3
4. -3x – 4y = -23 5. x – 3y = 11
-3x + y = 2
2x – 3y = 16
6. x – 2y = 6
x+y=3
7. 2a – 3b = -13
2a + 2b = 7
9. 5x – y = 6
5x + 2y = 3
8. 4x + 2y = 6
4x + 4y = 10
Multiply
Use elimination to solve each system of equations.
1. 2x + 3y = 6
2. 2m + 3n = 4
3. 3a - b = 2
x + 2y = 5
-m + 2n = 5
a + 2b = 3
4. 4x + 5y = 6
6x - 7y = -20
5. 4x – 3y = 22
2x – y = 10
7. 4x – y = 9
5x + 2y = 8
8. 4a – 3b = -8
2a + 2b = 3
6. 3x – 4y = -4
x + 3y = -10
9. 2x + 2y = 5
4x - 4y = 10
Practice
Worksheet
Work book:
Pages 115 and 116 #1-14, not #6