Lesson 11-8 Graphing Linear Inequalities pp EQ: How do you solve systems of linear equations by graphing?

Vocabulary to look for in this lesson: Boundary Half plane EQ: How do you solve systems of linear equations by graphing?

To graph an inequality such as y<x+1, first graph the related equation y = x + 1. This is the boundary. – If the inequality contains the symbol ≤ or ≥, a solid line is used to show that the boundary is included in the graph. – If the inequality contains the symbol, a dashed line is used to indicate that the boundary is not included in the graph

Next, test any point above or below the line to decide which region is the solution for y<x+1. – For example, it is easy to test (0,0)

Since 0<1 is true, (0,0) is a solution of y<x+1. Shade the region that contains this solution. This region is called a half plane. All points in this region are solutions of the inequality.

Example – Graph an Inequality

The solution of an inequality includes negative numbers and fractions too. In real life situations, though, sometimes negative numbers and fractions have no meaning.

Example – Graph an Inequality to Solve a Problem

Class work: p. 550 # 3-7 all Homework: pp. 550 # 8-22 evens EQ: How do you solve systems of linear equations by graphing?