7.5: Linear Inequalities
Objective- To graph linear inequalities and write/use them in real world situations.
Vocabulary:
1. Linear Inequality- _____________________________________________________________
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2. Solution of an Inequality- _______________________________________________________
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Investigate: Graphing Inequalities
1. Graph y = x + 4 on the coordinate plane.
2. Test 3 points that lie above the line y = x + 4. Substitute the coordinates of the point (x, y) in the
inequality y > x + 4. If the results are true statements, mark the points on the graph.
3. Test 3 points that lie below the line y = x + 4. Substitute the coordinates of the point (x, y) in the
inequality y > x + 4. If the results are true statements, mark the points on the graph.
4. Critical Thinking:
To graph y > x + 4, would you choose points above or below y = x + 4?
5. Determine with out graphing whether you would choose points above or below the graph of y = x – 2
to graph y < x – 2.
Notes:
Symbol
> or <
 or 
Line
Example 1: Graphing an Inequality
a.) y > -2x + 1
b.) y  4/3x - 9
c.) y > x -1
Example 2: Real World Problem Solving
Budget- Suppose your budget allows you to spend no more than $24 for decorations for a party.
Streamers cost $2 for a roll and table cloths cost $6 each. Graph the inequality that represents the
situation.