1. 4-5 SOLVING INEQUALITIES USING ADDITION AND SUBTRACTION MISS BATTAGLIA – ALGEBRA 1 CP OBJECTIVE: USE ADDITION AND SUBTRACTION TO SOLVE ONE-STEP INEQUALITIES; USE INEQUALITIES TO MODEL REAL-WORLD PROBLEMS.

2. WARM UP Jackie has $3.50 in quarters and nickels. If she has two more quarters than nickels, how many quarters does Jackie have?

3. WORK WITH A PARTNER Define a variable and write an equality for each sign. 12 3

4. WORK WITH A PARTNER Define a variable and write an equality for each situation. 1)Persons under 17 are not admitted. 2)Visibility at the airport is less than 2 miles. 3)You must be more than 36 in. tall to ride an amusement park ride.

5. SOLUTION OF THE INEQUALITY Any value of the variable that makes the inequality true is called a solution of the inequality. Tell whether each number is a solution of x < 3. a)1b) – 7.3c) 9.00 d) 0e) 3

6. GRAPHING INEQUALITIES x < 4 An open dot means 5 is not a solution. x < 4 A closed dot means 5 is a solution.

7. GRAPH x > -1 x > -1

8. EQUIVALENT INEQUALITIES Equivalent Inequalities have the same set of solutions. -4 < 1 -4 + 2 < 1 + 2 -2 < 3

9. PROPERTIES OF INEQUALITY Addition Property of Inequality For any numbers a, b, and c, if a > b then a + c > b + c For any numbers a, b, and c, if a < b then a + c < b + c Subtraction Property of Inequality For any numbers a, b, and c, if a > b then a - c > b - c For any numbers a, b, and c, if a < b then a - c < b - c

10. GRAPH THE SOLUTION ON A NUMBER LINE. x – 3 < 5

11. GRAPH THE SOLUTION ON A NUMBER LINE. w + 2 > -1

12. GRAPH THE SOLUTION ON A NUMBER LINE. 5.7 > k – 3.1

13. EXAMPLE Your bank offers free checking for accounts with a balance of at least $500. Suppose you have a balance of $516.46 and you write the check below. How much must you deposit to avoid being charged a service fee?

14. HOMEWORK Pg 182 #1-6, 8, 10, 12, 17,18, 29–35 odd