1. Solving One-Step Equations and Inequalities-Chapter 2

2. 2-1 Properties of Numbers
Objective 1: Identifying Properties
Commutative Properties of Addition
and Multiplication
Changing the order of the values you are adding or multiplying does not change the sum or product.

3. Associative Properties of Addition and Multiplication
Changing the grouping of the values you are adding or multiplying does not change the sum or product.

4. Real-World    Problem Solving
Golf Carlos rented a set of golf clubs for $7 and a golf cart for $12. He paid a greens fee of $23. Find his total cost.
Use the associative property to solve this.

5. When you add a number and 0, the sum equals the original number
When you add a number and 0, the sum equals the original number. The additive identity is 0. When you multiply a number and 1, the product equals the original number. The multiplicative identity is 1.
Identity Properties of Addition and Multiplication
The sum of any number and zero is the original number. The product of any number and 1 is the original number.

6. 5x7=7x5 C x 1= c 7+a=a+7 5(xy)=(5x)y Identifying Properties
Name each property shown.
5x7=7x5
C x 1= c
7+a=a+7
5(xy)=(5x)y

7. Objective 2: Using Properties
Using Mental Math With Addition
Use mental math to simplify (81 + 6) + 9.

8. Real-World Problem Solving
School Supplies Suppose you buy the school supplies shown at the left. Use mental math to find the cost of the supplies.

9. Using Mental Math With Multiplication
Use mental math to simplify (4 • 9) • 5.

10. 2-2 The Distributive Property
Objective 1: Numerical Expressions
Distributive Property
To multiply a sum or difference, multiply each number within the parentheses by the number outside the parentheses.
Using the Distributive Property I
Use the Distributive Property to find 20(102) mentally.

11. Real-World Problem Solving
Fundraising At the Parent-Teacher Association (PTA) Pancake Breakfast, the PTA served 397 people 4 pancakes each. How many pancakes did the PTA serve?

12. Using the Distributive Property II
Simplify 8(15) − 8(5).

13. Using Tiles to Multiply
Use algebra tiles to multiply 3(2x + 5).

14. Using the Distributive Property III
Multiply
-5(4x-3)
(2x+5)7

15. Coefficients Like Terms Constants
2-3 Simplifying Variable Expressions
Objective 1: Identifying Parts
of a variable expression
Identifying Parts of an Expression
Name the coefficients, the like terms, and the constants in 3m − 2n + n − 4.
Coefficients Like Terms Constants

16. Objective 2: Simplifying Variable Expressions
You simplify a variable expression by replacing it with an equivalent expression that has as few terms as possible. Algebra tiles can help you model this process.
Using Tiles to Simplify
Simplify 2x x.

17. Combining Like Terms Simplify 5y + y.
Deductive reasoning is the process of reasoning logically from given facts to a conclusion. As you use properties, rules, and definitions to justify the steps in a problem, you are using deductive reasoning.

18. 2-4 Variables and Equations
Objective 1: Classifying Types of Equations
An equation is a mathematical sentence with an equal sign. Here are three of the ways you will see equations in this book.
An equation with a numerical expression equal to another numerical expression is either true or false. An equation with one or more variables is an open sentence.
Classifying Equations
State whether each equation is true, false, or an open sentence.
6+12=18
6=4+3
6y=-3+5y

19. Nine times the opposite of five is forty-five.
Writing an Equation
Write an equation for
Nine times the opposite of five is forty-five.
Objective 2: Checking Equations Using Substitution
A solution of an equation is a value for a variable that makes an equation true. You substitute a number for a variable to determine whether the number is a solution of the equation.
Substituting to Check
Is 30 a solution of the equation x = 200?

20. Real-World Problem Solving
Scuba Diving A diver's equipment weighs 35 lb. The diver plus the equipment weighs 165 lb. Can the diver's weight be 200 lb?

21. 2-5 Solving Equations by Adding or Subtracting
Objective 1: Using Subtraction to Solve Equations
When you solve an equation, your goal is to get the variable alone on one side of the equation. The value on the other side tells you the solution of the original equation. You use inverse operations, which undo each other, to get the variable alone.
Subtraction Property of Equality
You can subtract the same number from each side of an equation.

22. Subtracting to Solve an Equation
Solve x + 6 = 4
Real-World   Problem Solving
Health Fred's target heart rate is 130 beats/min. This is 58 beats/min more than his resting heart rate. Find his resting heart rate.

23. Objective 2: Using Addition to Solve Equations
Addition Property of Equality
You can add the same number to each side of an equation.
Adding to Solve an Equation
Solve b − 12 = −49.

24. Real-World Problem Solving
Purchasing Your friend's VCR cost $328 less than her TV. Her VCR cost $179. How much did her TV cost?

25. 2-6 Solving Equations by Multiplying or Dividing
Objective 1: Using Division to Solve Equations
Division Property of Equality
If you divide each side of an equation by the same nonzero number, the two sides remain equal.

26. Real-World Problem Solving
Statistics The United States population in 1998 was twice the population in Find the 1943 population in millions.
Let P =population in
1943

27. Dividing to Solve an Equation
Solve 5r = −20.

28. Multiplication Property of Equality
Objective 2: Using Multiplication to Solve Equations
Multiplication Property of Equality
You can multiply each side of an equation by the same number.
Multiplying to Solve an Equation
Solve    = −3.

29. 2-8 Inequalities and Their Graphs
An inequality is a mathematical sentence that contains >, <, ≥, ≤, or ≠. Some inequalities contain a variable. Any number that makes an inequality true is a solution of the inequality. For example, −4 is a solution of y ≥ −5 because −4 ≥ −5.
Objective 1: Graphing Inequalities
An Open dot means that the inequality has line
A Closed dot means that the inequality has line
Graphing Solutions of Inequalities
Graph the solutions of each inequality on a number line.
y < 3
x > −1
a ≤ −2
−6 ≤ g

30. Objective 2: Writing Inequalities
Writing Inequalities to Describe Graphs
Write the inequality shown in each graph
-1 0
Real-World Problem Solving
Nutrition Food can be labeled low sodium only if it meets the requirement established by the federal government. Use the table to write an inequality for this requirement.

31. 2-9 Solving One-Step Inequalities by Adding or Subtracting
Objective 1: Solving Inequalities by Subtracting
Subtraction Property of Inequality
You can subtract the same number from each side of an inequality.

32. Subtracting to Solve an Inequality
Solve each inequality. Graph the solutions.
n + 8 ≥ 19
−26 > y + 14

33. Real-World Problem Solving
Computers Nearly 32 megabytes (MB) of memory are available for running your computer. If its basic systems require 12 MB, how much memory is available for other programs?

34. Adding to Solve an Inequality
Objective 2: Using Addition to Solve Inequalities
You can add the same number to each side of an inequality.
Adding to Solve an Inequality
Solve n − 15 < 3.

35. 2-10 Solving One-Step Equations by Multiplying or Dividing

36. Real-World Problem Solving
Engineering An elevator can carry up to 2,500 lb. Suppose the weight of an average adult is 150 lb. At most how many average-sized adults can safely ride the elevator at the same time?
Multiplying to Solve an inequality
Solve  ≥ 7.