1. 2.8 Graph Linear Inequalities in Two Variables

2. In this lesson you will:
Graph linear inequalities in two variable.
Use linear inequalities to solve real-life problems.

3. A Linear Inequality in two variables can be written in one of these forms:
Ax+By<C
Ax+By>C
An ordered pair (x,y) is a solution of a linear inequality if the inequality is true when the values of x an y are substituted into the inequality.
For example: (-6,2) is a solution of y>3x-9 because 2>3(-6)-9 is a true statement.

4. Which of these ordered pairs are solutions of 2x + 3y > 5?
(0,1)?
(4,-1)?
(2,1)?

5. Graph y < 2x Test a point in one of the half-plane ( test (5,0))
Graph the boundry line y = 2x
Test a point in one of the half-plane ( test (5,0))
Why is the “boundry line” “dashed” rather than solid?
Why is the “right” shaded rather than the “left”?

6. Graph the linear inequality 2x-5y>10
Graph the “boundary line” 2x-5y=10.
Test a point in one of the half-planes (e.g. (0,0))