Warm up Feb 5, 2013 Rewrite each in slope intercept form:

1. 30x + 5y = 52. x – y = -53. 4x + 2y = -64. 2x – 4y = 65. 3x + 5y = 15

CCGPS Coordinate AlgebraDay 19 (2-1-13)

UNIT QUESTION: How do I justify and solve the solution to a system of equations or inequalities?Standard: MCC9-12.A.REI.1, 3, 5, 6, and 12

Today’s Question:When is it better to use substitution than elimination for solving systems?Standard: MCC9-12.A.REI.6

Solve Systems of Equations by

Graphing

Steps to Graphing

1. Make sure each equation is in slope-intercept form: y = mx + b.

2. Graph each equation on the same graph paper.

3. The point where the lines intersect is the solution. If they don’t intersect then there’s no solution.

4. Check your solution algebraically.

2 2 8

2 2 4

x y

x y

1. Graph to find the solution.

Solution: (-1, 3)

2 5

2 1

y x

y x

No Solution

2. Graph to find the solution.

2

2 3 9

x y

x y

Solution: (-3, 1)

3. Graph to find the solution.

Solution: (-2, 5)

4. Graph to find the solution.

5

2 1

y

x y