Solving systems of equations graphically

The  exercise appears under the 8th Grade Math Mission. This exercise draws systems of equations on the coordinate plane and uses the picture to find the solution.

Types of Problems
There is one type of problem in this exercise:


 * 1) Graph the lines and find the intersection: This problem provides a Cartesian coordinate plan and a couple equations of lines. The student is asked to draw the lines on the plan, and give the solution to the system.Gsoe1.png

Strategies
Necessary skills include an ability to graph lines. Other skills, such as solving system of equations, are useful but not necessary.
 * 1) The solution to a system of equations is the point where the lines intersect.
 * 2) The manipulative is straight-forward to use and the lines are color-coded.
 * 3) The point of intersection will always be integral (both coordinates will be integers) so if the point is in between grid points and error has occurred.
 * 4) There is no need to solve the system separately, the graph should yield the solution if done correctly.
 * 5) The lines are given in slope-intercept form, so one method to graph would be to place one point at the y-intercept, then use the rise over run of the slope to get a second point.