Linear Inequalities Solution to inequality in one variable – interval on number line Solution to inequality in two variables – points in the plane Graph equation Use solid line or curve if ≤ or ≥. Use dashed if < or >. Test a point to see if it belongs or not. Shade appropriate region. Solution to system of inequalities in two variables – overlap Do above steps for each inequality. The shaded overlap is the solution, all points that satisfy all inequalities.

Example 1 4 2 2 6 Does (0, 0) satisfy the inequality?

Example 2 Intersections? Does (0, 0) satisfy first inequality? 4 2 2 6 Does (0, 0) satisfy first inequality? So every point in the region with (0, 0) is Does (0,0) satisfy second inequality?

Example 3 Intersection? 80 60 40 Corner Points: 20 80 100

Example 4 Intersections? 8 6 4 Corner Points: 2 8 10

Example 5 Intersection? Corner Points: 60 50 40 30 20 10 20 40 60 80 100