Final answer:
To write and graph an inequality for a given solution set, use the appropriate inequality symbol and plot the corresponding graph on a number line.
Step-by-step explanation:
In Exercises 21-23, we are asked to write and graph an inequality for the given solution set.
For example, in Exercise 21, the solution set is x > 3. To write the inequality, we use the symbol > to represent 'greater than'. So the inequality would be x > 3.
To graph this inequality, we plot an open circle at 3 on the number line and shade to the right to represent all values greater than 3.