Introduction to Inequalities

Students learn that an inequality is a mathematical sentence that states that two expressions are not equal. For example, x < 9, which is read, "x is less than 9", means that any number less than 9 is a solution to the inequality. So 8, 7, 5.9, 0, and –10 are all solutions to x < 9. Note that the following symbols are used to represent inequalities: < (less than), > (greater than), < underlined (less than or equal to), and > underlined (greater than or equal to). In the problems in this lesson, students are asked to write two solutions to given inequalities. Students are also asked to determine if a given value is a solution to a given inequality.