C H A P T E R BUILD YOUR VOCABULARY This is an alphabetical list of new vocabulary terms you will learn in Chapter. As you complete the study notes for the chapter, you will see Build Your Vocabulary reminders to complete each term s definition or description on these pages. Remember to add the textbook page number in the second column for reference when you study. Vocabulary Term Found on Page Definition Description or Example absolute value additive inverse average coordinate inequality 3 Glencoe Pre-Algebra
Chapter BUILD YOUR VOCABULARY Vocabulary Term Found on Page Definition Description or Example integer mean negative number opposites quadrants Glencoe Pre-Algebra 33
1 Integers and Absolute Value MAIN IDEAS Compare and order integers. Find the absolute value of an expression. BUILD YOUR VOCABULARY (pages 3 33) A negative number is a number less than zero. Negative numbers like -8, positive numbers like +6, and are members of the set of integers. The that corresponds to a is called WRITE IT List 5 words or phrases that indicate positive or negative numbers. the coordinate of that point. Any mathematical sentence containing or is called an inequality. EXAMPLE Write Integers for Real-World Situations Write an integer for each situation. a. 3 feet underground The integer is. b. 8 weeks after birth The integer is. c. a loss of 6 pounds The integer is. Check Your Progress situation. a. a loss of 1 yards b. 15 feet above sea level Write an integer for each c. the temperature decreased 4 degrees 34 Glencoe Pre-Algebra
1 EXAMPLE Compare Two Integers Use the integers graphed on the number line below. 4 0 4 6 8 a. Write two inequalities involving 7 and -4. Since 7 is to the of -4, 7-4. Since -4 is to the of 7, -4 7. b. Replace the with <, >, or = in - 3 to make a true sentence. 3 is since it lies to the of -. So, - 3. Check Your Progress number line below. Use the integers graphed on the a. Write two inequalities involving -4 and 1. b. Replace the with <, >, or = in 6-7 to make a true sentence. EXAMPLE Order Integers WEATHER The high temperatures for the first seven days of January were -8, 10,, -3, -11, 0, and 1. Order the temperatures from least to greatest. Graph each integer on a number line. 1 10 8 6 4 0 4 6 8 10 The order from least to greatest is. Glencoe Pre-Algebra 35
1 Check Your Progress FOOTBALL The yards gained during the first six plays of the football game were 5, -3, 1, -9, 6 and -1. Order the yards from least to greatest. KEY CONCEPT Absolute Value The absolute value of a number is the distance the number is from zero on the number line. The absolute value of a number is always greater than or equal to zero. BUILD YOUR VOCABULARY (page 3) Two numbers have the same absolute value if they are on sides of zero, and are the same from zero. EXAMPLE Expressions with Absolute Value Evaluate each expression. a. 5 The graph of 5 is 5 units from 0. 5 = b. -8 + -1 HOMEWORK ASSIGNMENT Page(s): Exercises: -8 + -1 = -8 =, -1 = = Simplify. Check Your Progress Evaluate each expression. a. -9 b. -3 + EXAMPLE Algebraic Expressions with Absolute Value ALGEBRA Evaluate the expression x - 8 if x = -. x - 8 = - 8 Replace x with. = - 8 The absolute value of is. = Simplify. Check Your Progress ALGEBRA Evaluate the expression 5 - x if x = 9. 36 Glencoe Pre-Algebra
Adding Integers EXAMPLE Add Integers on a Number Line MAIN IDEAS Add two integers. Find 3 + 4. 3 4 Add more than two integers. 0 1 3 4 5 6 7 8 Start at. Move units to the. From there, move more units to the. 3 + 4 = Check Your Progress Find - + -5. KEY CONCEPT Adding Integers with the Same Sign To add integers with the same sign, add their absolute values. Give the result the same sign as the integers. ORGANIZE IT Under the + tab, write a sum of integers with different signs, and explain how to add them on a number line. EXAMPLE Add Integers with the Same Sign Find -5 + (-4). -5 + (-4) = Add and. Both numbers are so the sum is. Check Your Progress Find -3 + -8. -6-5-4-3 - -1 1 3 4 5 6 Glencoe Pre-Algebra 37
EXAMPLE Add Integers on a Number Line Find 7 + (-11). 11 7 6 5 4 3 1 0 1 3 4 5 6 7 Start at. Move units to the. From there, move units to the. 7 + (-11) = Check Your Progress Find each sum. a. -5 + 8 b. 3 + (-6) EXAMPLE Add Integers with Different Signs KEY CONCEPT Adding Integers with Different Signs To add integers with different signs, subtract their absolute values. Give the result the same sign as the integer with the greater absolute value. a. Find -9 + 10. -9 + 10 = To fi nd -9 + 10, subtract b. Find 8 + (-15). from because 10 > -9.. The sum is positive 8 + (-15) = -7 To fi nd 8 + (-15), subtract from. The sum is negative because -15 > 8. Check Your Progress Find each sum. a. -6 + 11 b. 4 + (-7) 38 Glencoe Pre-Algebra
BUILD YOUR VOCABULARY (pages 3 33) Two numbers with same absolute value but different are called opposites. An integer and its additive inverses. are called EXAMPLE WEATHER On February 1, the temperature at dawn was - F. By noon, it has risen 19 degrees. What was the temperature at noon? Words Variable temperature plus increase equals temperature at dawn by noon at noon Let =. Equation + = - + 19 = To fi nd the sum, subtract from. The sum is negative because <. The temperature at noon was. Check Your Progress HIKING Dave started his hike at 3 feet below sea level. During the hike he gained an altitude of 9 feet. At what altitude did Dave complete his hike? Glencoe Pre-Algebra 39
EXAMPLE Add Three or More Integers a. Find -8 + (-4) + 8. KEY CONCEPT Additive Inverse Property The sum of any number and its additive inverse is zero. -8 + (-4) + 8 = -8 + Commutative Property = + -4 Additive Inverse Property = Identity Property of Addition b. Find 6 + (-3) + (-9) +. 6 + (-3) + (-9) + = 6 + Commutative Property = [6 + ] + Associative Property = 8 + or Simplify. HOMEWORK ASSIGNMENT Page(s): Exercises: Check Your Progress Find each sum. a. 3 + (-9) + (-3) b. - + 11 + (-4) + 5 40 Glencoe Pre-Algebra
3 Subtracting Integers EXAMPLE Subtract a Positive Integer MAIN IDEAS Subtract integers. Evaluate expressions containing variables. Find each difference. a. 9-14 9-14 = 9 + To subtract 14, add. = Simplify. KEY CONCEPT Subtracting Integers To subtract an integer, add its additive inverse. b. -10-8 -10-8 = -10 + To subtract 8, add. = Simplify. Check Your Progress Find each difference. a. 6-8 b. -9-13 ORGANIZE IT Write two examples of subtracting a negative number from a positive number under the - tab. -6-5-4-3 - -1 1 3 4 5 6 EXAMPLE Subtract a Negative Integer Find each difference. a. 15 - (-4) 15 - (-4) = 15 + To subtract -4, add. = Simplify. b. -11 - (-7) -11 - (-7) = -11 + To subtract -7, add. = Simplify. Check Your Progress Find each difference. a. 8 - (-) b. -1 - (-5) Glencoe Pre-Algebra 41
3 EXAMPLE Evaluate Algebraic Expressions a. Evaluate m - (-) if m = 4. m - (-) = - (-) Replace m with. = To subtract -, add. = Add and. b. Evaluate x - y if x = -14 and y = -. x - y = - ( ) Replace x with and y with. = To subtract -, add. = Add and. Check Your Progress a. Evaluate p - (-6) if p = -4. HOMEWORK ASSIGNMENT Page(s): Exercises: b. Evaluate m - n if m = -9 and n = -3. 4 Glencoe Pre-Algebra
4 Multiplying Integers EXAMPLE Multiply Integers with Different Signs MAIN IDEAS Multiply integers. Simplify algebraic expressions. Find 8(-9). 8(-9) = The factors have different signs. The product is. KEY CONCEPT Multiplying Integers The product of two integers with different signs is negative. The product of two integers with the same sign is positive. EXAMPLE Multiply Integers with the Same Sign Find -4(-16). -4(-16) = The two factors have the same sign. The product is. Check Your Progress Find each product. a. -4(1) b. -3(-8) ORGANIZE IT In your own words, describe how to multiply integers under the tab. Give examples of all cases. EXAMPLE TEST EXAMPLE A student missed only four problems on a test, each worth 0 points. What integer represents the total number of points earned for those questions? A -5 B -0 C 4 D -80 4(-0) = The product is. The answer is. Check Your Progress TEST EXAMPLE A football team loses 3 yards on each of 3 consecutive plays. What integer represents the total loss? A -9 C 6 B -6 D 9-6 -5-4 -3 - -1 1 3 4 5 6 Glencoe Pre-Algebra 43
4 EXAMPLE Simplify and Evaluate Algebraic Expressions a. Simplify 8a(-5b). 8a(-5b) = (8)(a)(-5)(b) = (8-5)(ab) Commutative Property of Multiplication = 8-5 =, a b = WRITE IT What is the name of the property that allows you to regroup the numbers and the variables being multiplied? b. Evaluate -3xy if x = -4 and y = 9. -3xy = -3 x = -4 and y = 9. = (9) Associative Property of Multiplication = (9) The product of and is positive. = The product of HOMEWORK ASSIGNMENT Page(s): Exercises: and Check Your Progress a. Simplify 5m(-7n). b. Evaluate -9ab if a = -3 and b = -6. is positive. 44 Glencoe Pre-Algebra
5 Dividing Integers EXAMPLE Divide Integers with the Same Sign MAIN IDEAS Divide integers. Find the average of a set of data. KEY CONCEPTS Dividing Integers with the Same Sign The quotient of two integers with the same sign is positive. Dividing Integers with Different Signs The quotient of two integers with different signs is negative. a. Find -8 (-4). -8 (-4) = The dividend and the divisor have the same sign. The quotient is b. Find _ 96 8. _ 96 8 = 96 8 The dividend and the divisor have the same sign. = The quotient is. Check Your Progress Find each quotient. a. 35 7 b. _ -64-4. EXAMPLE Divide Integers with Different Signs a. Find 54 (-3). 54 (-3) = The signs are different. The quotient is. _ b. Find -4 6 _. -4 = -4 6 The signs are different. The 6 quotient is. = Simplify. Check Your Progress Find each quotient. a. 7 (-8) b. _ -36 4 Glencoe Pre-Algebra 45
5 EXAMPLE Evaluate Algebraic Expressions Evaluate 6x y if x = -4 and y = -8. 6x y = 6 x = -4 and y = -8 = (-8) 6(-4) = = The quotient is. Check Your Progress Evaluate -4m n if m = -9 and n = -3. BUILD YOUR VOCABULARY (pages 3 33) ORGANIZE IT Describe how to find the average of a set of numbers in your own words under the tab. -6-5-4-3 - -1 1 3 4 5 6 HOMEWORK ASSIGNMENT Page(s): Exercises: To find the average, or mean, of a set of numbers, find the number in the set. EXAMPLE Find the Mean of the numbers and then by the a. Ian had exam scores of 89, 98, 96, 97, and 95. Find the average (mean) of his scores. 89 + 98 + 96 + 97 + 95 Find the sum of the scores. Then divide by the number of scores. = or Simplify. Check Your Progress Kyle had test scores of 89, 8, 85, 93, and 96. Find the average (mean) of his test scores. 46 Glencoe Pre-Algebra
6 The Coordinate System EXAMPLE Write Ordered Pairs MAIN IDEAS Graph points on a coordinate plane. Graph algebraic relationships. Write the ordered pair that names each point. a. P y The x-coordinate is. The y-coordinate is. The ordered pair is. 4 3 1 4 3 1 O1 1 Q 3 4 R 3 4 x P REMEMBER IT The coordinates in an ordered pair (x, y) are listed in alphabetical order. b. Q The x-coordinate is. The y-coordinate is. The ordered pair is. Check Your Progress names each point. a. M b. N c. P Write the ordered pair that BUILD YOUR VOCABULARY (pages 3 33) The x-axis and the y-axis separate the coordinate 4 3 1 4 3 1 O1 3 4 x 1 P N M 3 4 y plane into regions, called quadrants. Glencoe Pre-Algebra 47
6 EXAMPLE Graph Points and Name Quadrant REVIEW IT Give a definition for the origin of a coordinate system. ( Lesson 1-5) Graph and label each point on a coordinate plane. Then name the quadrant in which each point lies. a. S(-1, -5) y Start at the origin. Move unit. Then move units and draw a dot. Quadrant. 3 1 4 3 1 O1 1 3 4 x 3 4 5 S b. U(-, 3) y 3 U Start at the origin. Move units. Then move units 1 4 3 1 O 1 1 3 4 5 3 4 x and draw a dot. Quadrant. c. T(0, -3) y Start at the origin. Since the x-coordinate is 0, the point lies on the. Move 3 units down, and draw a dot. Point T is not in any quadrant. 3 1 4 3 1 O1 1 3 4 x T 3 4 5 Check Your Progress Graph and label each point on a coordinate plane. Name the quadrant in which each point lies. a. A(3, -4) b. B(-, 1) c. C(-4, 0) 4 3 1 y 4 3 1 O1 1 3 4 x 3 4 48 Glencoe Pre-Algebra
6 EXAMPLE Graph an Algebraic Relationship The difference between two integers is 4. If x represents the first integer and y is subtracted from it, make a table of possible values for x or y. Then graph the ordered pairs and describe the graph. First, make a table. Choose values for x x - y = 4 and y that have a x y (x, y) difference of 4. 1 0-1 - HOMEWORK ASSIGNMENT Page(s): Exercises: Then graph the ordered pairs on a coordinate plane. The points on the graph are in a line that slants upward to the right. The line crosses the y-axis at -4. 1 4 3 1 O 1 3 4 x 1 3 4 5 6 Check Your Progress The sum of two integers is 3. If x is the first integer and y represents the second number, make a table of possible values for x and y. Graph the ordered pairs and describe the graph. 4 3 1 y 4 3 1 O1 1 3 4 x 3 4 y Glencoe Pre-Algebra 49
C H A P T E R BRINGING IT ALL TOGETHER STUDY GUIDE Use your Chapter Foldable to help you study for your chapter test. VOCABULARY PUZZLEMAKER To make a crossword puzzle, word search, or jumble puzzle of the vocabulary words in Chapter, go to: glencoe.com BUILD YOUR VOCABULARY You can use your completed Vocabulary Builder (pages 3 33) to help you solve the puzzle. -1 Integers and Absolute Value 1. Order the integers {1, -1, 9, 7, 0-4, -11} from least to greatest. Evaluate each expression if r = 3, s = -, and t = -7.. t - 6 3. 1 - s - 5 4. s + t - r 5. rt - 1 s - Adding Integers Find each sum. 6. -5 + 9 7. 7 + (-31) + 4 8. (-8) + + (-15) + 5 9. 6 + (-10) + (-1) + 4-3 Subtracting Integers Find each difference. 10. -17-6 11. 35 - (-14) 1. 4-19 13. 11 - (-18) 50 Glencoe Pre-Algebra
Chapter BRINGING IT ALL TOGETHER Evaluate each expression if p = -6, q = 9, and r = -. 14. q - 16 15. r - 4 16. p - q - r 17. q - r - p -4 Multiplying Integers Find each product. 18. -4(-16) 19. 3(-4)(-11)() Simplify each expression. 0. 5b (-7c) 1. p(-7q)(-3) -5 Dividing Integers Find each quotient.. 7-9 3. -8 4 4. _ -49-7 5. _-144 18 6. Find the average (mean) of 9, -6, 11, 7,, and -5. -6 The Coordinate System Name the ordered pair for each point graphed on the coordinate plane. 7. A 8. B 9. C B 4 3 1 4 3 1 O1 3 4 x 1 C 3 4 y A Glencoe Pre-Algebra 51