Systems of Linear Inequalities
One linear inequality in two variables divides the plane into two half-planes . To graph the inequality, graph the equation of the boundary. Use a solid line if the symbol or is used because the boundary is included in the solution. Use a dashed line if is used to indicate that the boundary is not part of the solution. Shade the appropriate region. Unless you are graphing a vertical line the sign of the inequality will let you know which half-plane to shade. If the symbol or is used, shade above the line. If the symbol or is used shade below the line. For a vertical line, larger solutions are to the right and smaller solutions are to the left. A system of two or more linear inequalities can divide the plane into more complex shapes.
Graph the system of linear inequalities.
Graphing the three lines and shading the region enclosed, we get the figure below.