Objectives To solve systems of equations by graphing To analyze special systems
You can model the problem in the Solve It with two linear equations. Two or more linear equations form a system of linear equations. Any ordered pair that makes all of the equations in a system true is a solution of a system of linear equations.
Essential Understanding You can use systems of linear equations to model problems. Systems of equations can be solved in more than one way. One method is to graph each equation and find the intersection point, if one exists.
What is the solution of the system? Use a graph.
Graph both equations in the same coordinate plane.
How does graphing each equation help you find the solution?
A line represents the solutions of one linear equation. The intersection point is a solution of both equations.
Find the point of intersection. The lines appear to intersect at (2, 4). Check to see if (2, 4) makes both equations true.
The solution of the system is (2, 4).