Linear Inequality
Definition of Linear Inequality
A Linear Inequality involves a linear expression in two variables by using any of the relational symbols such as <,>, = or =
More About Linear Inequality
 A linear inequality divides a plane into two parts.
 If the boundary line is solid, then the linear inequality must be either = or =.
 If the boundary line is dotted, then the linear inequality must be either > or <.>
Example of Linear Inequality
Video Examples: Solving Linear Inequalities
 As the boundary line in the above graph is a solid line, the inequality must be either = or =.
Since the region below the line is shaded, the inequality should be �=�.
We can notice that the line y =  2x + 4 is included in the graph; therefore, the inequality is y =  2x + 4. Any point in the shaded plane is a solution and even the points that fall on the line are also solutions to the inequality.  4x + 6y = 12, x + 6 = 14, 2x  6y < 12="" +="" 2x,="" 9y="">< 12="" +="" 2x="" are="" the="" examples="" of="" linear="" inequalities.="">
Solved Example on Linear Inequality
Ques: Which of the graphs best suits the inequality y < x="" ="">
Choices:
A. Graph 1B. Graph 2
C. Graph 3
D. Graph 4
Correct Answer: A
Solution:

Step 1: Since the inequality �involves less than� (<), use="" dashed="" boundary="" line="" to="" graph="" the="" inequality="" y="">< x="" ="" 4="" as="" in="" the="" below="" shown="">
Test (0, 0) in the inequality.
y < x="" �="" 4="" [substitute.]="">
0 < 0="" �="">
0 < ="" 4="">
Step 3: Since the inequality is false for (0, 0), shade the region that does not contain (0, 0).
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