Education Technology

Introduction to Solving Linear Systems by Graphing

Published on 11/14/2008

Activity Overview

Students will use Activity Center to plot points that are solutions to linear equations and discover where the solution to the linear system lies. This introduces students to the concept that the solution to a linear system in two variables is the point that lies on the graphs of both equations.

Before the Activity

Pre-requisite knowledge: The students should already know how to:

  • determine solutions to a linear equation in two variables by constructing an input-output table, either by hand or on their handheld.
  • solve equations for y.
  • use y= and the table function on their handheld to enter an equation and determine ordered pairs that are solutions to that equation.

  • Teacher should pre-select several linear systems that have integer solutions. (see activity attachment).

    During the Activity

    Divide the class into two groups and assign one equation from the linear system to each group. Each member of the group finds one solution to the equation by using the table function on their handheld. Teacher sets up Activity Center as described in the attached detailed activity description; students enter their points. When enough points have been entered to see the lines clearly, pause or stop the activity and determine the solution to the system, which will be the one point that is on both lines.

    After the Activity

    Assessment: Use the attached Activity Center settings to project more linear systems; have students determine the solution to the system by examining the graphs, use Quick Poll to have students enter their responses.