Solving an inequality involves following the same steps you use for solving an equation except for one crucial detail: When you multiply or divide by a negative number, you must flip the inequality symbol. Just like with equations, you can still check your answers by substituting them back into the original.
It's important to note that < or > results in an open circle
on a number line because that value is not included as a solution;
The following examples illustrate some of the different types of inequality problems that you may encounter.
Example 1: Linear inequality
Check: You want to pick a value in the solution set. Because your answer is x > 3, you have to pick a value greater than 3. For this example, you use 5.
Example 2: Linear inequality with negative coefficient
Example 3: Does not equal
Check: For this type of problem, you can pick any number except 1/2. So for this example, you can pick 1 to check your solution.