1. 9.6 Solving Systems of Equations by Graphing

2. Systems of Equations A pair of equations with two variables
A solution is an ordered pair (x,y) that makes BOTH equations true.

3. Graph to Find the Solution
Solution is where the graphs intersect

4. When we graph a system of two linear equations, one of three things may happen:
one point of intersection. (consistent)
The lines are parallel. There is no solution (inconsistent)
The lines coincide. Thus the equations have the same graph and there is an infinite number of solutions. (dependent)

5. Solve by graphing: x + 2y = 7 and x = y + 4
(5,1) is the solution

6. Solve by graphing: 3y - 2x = 6 and 2x – 3y = 12
no solution

7. Solve by graphing: 3y - 2x = 6 and 2x – 3y = 6
Many solutions

8. Solve by graphing: x + 4y = -6 and 2x – 3y = 10
(2,-2)

9. Solve by graphing: y = 2x + 1 and 2y + 4x = 10
(1,3)

10. Assignment Page 423 (5-18) all