Inequalities and Their Graphs

A mathematical sentence that uses symbols such as <, ≤, ≠, > or ≥ to compare two quantities is called an inequality. It is a relationship between two numbers or mathematical expressions that are not equal.

Example:

i)      x is a real number less than or equal to 5.

                            x<= 5

ii) x is a real number greater than 8.   

                             x > 8                     

Example:          -3x > 12

                             Dividing both sides of an inequality by -3, we get

                             x < -4

Check Point                                             

 Graph the following inequalities on a number line:

1)        x < -2

2)        x >= 6                                                                                   

3)        2x – 1 <=7

4)        -3x + 1 <= 16

5)        4x + 3 > x + 24