2. Chapter 7 Lesson 3 Inequalities pgs. 340-344 What you’ll learn: Write inequalities Graph inequalities

3. Vocabulary Inequality (340): a mathematical sentence that contains   Is less than  Is fewer than  Is greater than  Is more than  Exceeds  is less than or equal to  is no more than  is at most  is greater than or equal to  is no less than  is at least Concept Summary Inequalities Memorize these signs!!!

4. Example 1: Write Inequalities with  or  Your age is less than 15 years Variable: Let a represent age Inequality: a  15 Your height is greater than 55 inches Variable: Let h represent height Inequality: h  55

5. Example 2: Write Inequalities with  or  Write an inequality for each sentence. A number increased by 14 is at least 25 Kyle’s earnings at $15 per hour were no more than $60. Let n represent the number Refer to the concept summary to determine which Inequality symbol to use n + 14  25 15h  60

6. Example 3: Use an Inequality The elevators in an office building have been approved for a maximum load of 3600 pounds. Write an inequality to describe a safe load. Words: the elevators can only hold a max of 3600 pounds This also means that the elevator can hold less than 3600 pounds Which inequality symbol should we use? Read carefully to determine! A max of 3600 pounds means 3600 pounds or less. We should use  Let m = max weight Inequality: m  3600

7. Example 4: Determine Truth of an Inequality This is like a check for an equation! For the given value, state whether each inequality is true or false n + 4  6, n = 12 14  7, c = 2 c Write the inequality: n + 4  6 Replace n with 12: 12 + 4  6 Simplify: 16  6 TRUE! 16 IS greater than or equal to 6 Replace c with 2: 14  7 2 Simplify: 7  7 FALSE! How could this problem be rewritten to make it true? By using  or 

8. Example 5: Graph Inequalities Done on board in class. Refer to notes. Graph each inequality on a number line. x > 6 x  6 x  6x  6

9. Remember: a  (closed circle) means the number IS included in the graph a (open circle) means the point is NOT included in the graph

10. Example 6: Write an Inequality See example 6 on pg. 342 and notes for Examples (sorry, number lines are a bear to make!!)

11. Your Turn! Write an inequality: The 10km race time of 86 minutes was at least twice as long as the winner’s time. 86  2w Five times a number is less than 65 5n  65

12. Still your turn :o) For the value given, state whether each inequality is true or false. 5k  35, k= 7 14 + n  23, n = 8 5(7)  35 35  35 FALSE 14 + 8  23 22  23 TRUE

13. And Again! Graph the inequality on a number line. n  -3d  5 Write an inequality for each graph: See the board.

14. Extra Practice is by the door on your way out!! Make sure you keep the  and straight when graphing and when interpreting graphs! Practice this!!