Chapter Nine:  Inequalities and Absolute Value

Take notes on the following topics.
Algebra 1 Notes

Chapter Nine

Section 9.1

Section 9.2

Section 9.3

Section 9.4

Section 9.5

Section 9.6

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 



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Section 9.5    Inequalities in Two Variables 

(Examples provided by Prentice Hall)

Part I: Solutions of Inequalities in Two Variables

Determine whether the ordered pair is a solution of the inequality.

 
Example 1   3x + 2y < 20; (4, 1)
3(4) + 2(1) < 20 or 14 < 20 is a true statement. The pair is a solution.

Part II: Graphing Inequalities in Two Variables

Graph each inequality on a coordinate plane.

 
Example 1   2x + 3y < 12
The graph contains the boundary line 2x + 3y = 12 [which contains the points (0, 4) and (6, 0)] and all the points on one side of the line. The point (0, 0) satisfies the inequality, thus the graph consists of the line and all the points on the same side as the point (0, 0).

Example 2 x < 3
The graph contains the vertical line x = 3 and all the points to the left of the line.

 

Take class notes.

Before starting your homework, rework the examples that are illustrated in this section of your textbook and the examples that I demonstrated in class. 

Then do your homework.

Write down questions (examples or concept that you do not understand).......then.............. Ask these questions in class.