Holt Algebra 2 Textbook

200 Pages·2006·5.18 MB·English

exploration
1-1 Sets of Numbers
A set is a group of items, such as a group of numbers. For example,
the numbers that appear on a telephone keypad form a set. The
items in a set are called elements.
1. One method of describing a set is to list its elements inside
a pair of braces, {t} . Use this notation to write the set of
numbers found on a telephone keypad. {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
2. You can also describe a set by describing its properties.
Describe the set of numbers found on a telephone keypad
without listing them.
Possible answer: whole numbers less than 10
3. List four numbers that are NOT included in the set you
described in Problem 2. Possible answer: 0.5, 1.75, (cid:1) (cid:1)8 , (cid:1)
THINK AND DISCUSS
4. Explain how terms such as natural numbers, whole
numbers, and integers can help you
describe a set.
111000 111000
5. Describe the set of numbers that
222000 222000
appear on a football field.
333000 333000
4. Possible answer: Using these types of terms to
444000 444000
describe a set is sometimes easier than listing each
555000 555000
element when a set is very large.
444000 444000
5. Possible answer: integer multiples of 10 that are
greater than or equal to 10 and less than or equal to 50 333000 333000
222000 222000
111000 111000
1 Holt Algebra 2
All rights reserved.
exploration
1-1 Sets of Numbers
A set is a group of items, such as a group of numbers. For example,
the numbers that appear on a telephone keypad form a set. The
items in a set are called elements.
1. One method of describing a set is to list its elements inside
a pair of braces, {t} . Use this notation to write the set of
numbers found on a telephone keypad. {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
2. You can also describe a set by describing its properties.
Describe the set of numbers found on a telephone keypad
without listing them.
Possible answer: whole numbers less than 10
3. List four numbers that are NOT included in the set you
described in Problem 2. Possible answer: 0.5, 1.75, (cid:1) (cid:1)8 , (cid:1)
THINK AND DISCUSS
4. Explain how terms such as natural numbers, whole
numbers, and integers can help you
describe a set.
111000 111000
5. Describe the set of numbers that
222000 222000
appear on a football field.
333000 333000
4. Possible answer: Using these types of terms to
444000 444000
describe a set is sometimes easier than listing each
555000 555000
element when a set is very large.
444000 444000
5. Possible answer: integer multiples of 10 that are
greater than or equal to 10 and less than or equal to 50 333000 333000
222000 222000
111000 111000
1 Holt Algebra 2
All rights reserved.
exploration
1-2 Properties of Real Numbers
You may use a calculator to help you with the following problems.
Tell whether each statement is true or false.
1. 6 (cid:1) (cid:1)(cid:2)2 (cid:2) (cid:3) (cid:1)(cid:2)2(cid:2) (cid:1) 6 true 2. 8 (cid:2) (cid:1)(cid:2)2(cid:2) (cid:3) (cid:1)(cid:2)2(cid:2) (cid:2) 8 false
(cid:2) (cid:2) (cid:3) (cid:2) (cid:2) (cid:4) (cid:4) (cid:3) (cid:4) (cid:4)
3. 5 4 1 1 4 5 false 4. 20 5 2 2 5 20 false
5. 3(cid:1)7(cid:2) (cid:3) 7(cid:1)3 (cid:2) true 6. 7 (cid:1) 3 (cid:1) 2 (cid:3) 2 (cid:1) 7 (cid:1) 3 true
(cid:4) (cid:3) (cid:4) (cid:5) (cid:5) (cid:3) (cid:5) (cid:5)
7. 9 3 3 9 false 8. 10 20 30 30 20 10 true
9. Based on your answers to Problems 1–8, for which operations
(addition, subtraction, multiplication, and division) does the
order of the numbers make a difference in the result?
subtraction and division
Tell whether each statement is true or false.
10. (cid:1)8 (cid:4) 4(cid:2) (cid:4) 2 (cid:3) 8 (cid:4) (cid:1)4 (cid:4) 2(cid:2) 11. (cid:1)9 (cid:1) 4(cid:2) (cid:1) 3 (cid:3) 9 (cid:1) (cid:1)4 (cid:1) 3 (cid:2)
false true
12. (cid:1)5 (cid:2) 4 (cid:2) (cid:2) 1 (cid:3) 5 (cid:2) (cid:1)4 (cid:2) 1 (cid:2) 13. 21 (cid:5) (cid:1)32 (cid:5) 43(cid:2) (cid:3) (cid:1)21 (cid:5) 32(cid:2) (cid:5) 43
false true
14. Based on your answers to Problems 10–13, for which operations
(addition, subtraction, multiplication, and division) does the
grouping of the numbers make a difference in the result?
subtraction and division
THINK AND DISCUSS
15. Discuss how the properties you explored above might help
(cid:5) (cid:5)
you find 13 20 5 by using mental math.
16. Discuss whether it would matter which operation you did first
if you had more than one operation in a problem.
15. Possible answer: The grouping of the numbers does not make a difference in multiplication.
Group 20 and 5 because these two numbers are easy to multiply mentally. 13 (cid:1) (cid:2) 20 (cid:1) 5 (cid:3) (cid:2)
13 (cid:1) 100 (cid:2) 1300
16. Possible answer: Yes; in some cases, the order of operations would matter. For example,
if you simplified 2 (cid:3) 3 (cid:1) 4 by adding first, you would get 20. If you simplified 2 (cid:3) 3 (cid:1) 4 by
multiplying first, you would get 14.
Copyright © by Holt, Rinehart and Winston. 2 Holt Algebra 2
All rights reserved.
exploration
1-2 Properties of Real Numbers
You may use a calculator to help you with the following problems.
Tell whether each statement is true or false.
1. 6 (cid:1) (cid:1)(cid:2)2 (cid:2) (cid:3) (cid:1)(cid:2)2(cid:2) (cid:1) 6 true 2. 8 (cid:2) (cid:1)(cid:2)2(cid:2) (cid:3) (cid:1)(cid:2)2(cid:2) (cid:2) 8 false
(cid:2) (cid:2) (cid:3) (cid:2) (cid:2) (cid:4) (cid:4) (cid:3) (cid:4) (cid:4)
3. 5 4 1 1 4 5 false 4. 20 5 2 2 5 20 false
5. 3(cid:1)7(cid:2) (cid:3) 7(cid:1)3 (cid:2) true 6. 7 (cid:1) 3 (cid:1) 2 (cid:3) 2 (cid:1) 7 (cid:1) 3 true
(cid:4) (cid:3) (cid:4) (cid:5) (cid:5) (cid:3) (cid:5) (cid:5)
7. 9 3 3 9 false 8. 10 20 30 30 20 10 true
9. Based on your answers to Problems 1–8, for which operations
(addition, subtraction, multiplication, and division) does the
order of the numbers make a difference in the result?
subtraction and division
Tell whether each statement is true or false.
10. (cid:1)8 (cid:4) 4(cid:2) (cid:4) 2 (cid:3) 8 (cid:4) (cid:1)4 (cid:4) 2(cid:2) 11. (cid:1)9 (cid:1) 4(cid:2) (cid:1) 3 (cid:3) 9 (cid:1) (cid:1)4 (cid:1) 3 (cid:2)
false true
12. (cid:1)5 (cid:2) 4 (cid:2) (cid:2) 1 (cid:3) 5 (cid:2) (cid:1)4 (cid:2) 1 (cid:2) 13. 21 (cid:5) (cid:1)32 (cid:5) 43(cid:2) (cid:3) (cid:1)21 (cid:5) 32(cid:2) (cid:5) 43
false true
14. Based on your answers to Problems 10–13, for which operations
(addition, subtraction, multiplication, and division) does the
grouping of the numbers make a difference in the result?
subtraction and division
THINK AND DISCUSS
15. Discuss how the properties you explored above might help
(cid:5) (cid:5)
you find 13 20 5 by using mental math.
16. Discuss whether it would matter which operation you did first
if you had more than one operation in a problem.
15. Possible answer: The grouping of the numbers does not make a difference in multiplication.
Group 20 and 5 because these two numbers are easy to multiply mentally. 13 (cid:1) (cid:2) 20 (cid:1) 5 (cid:3) (cid:2)
13 (cid:1) 100 (cid:2) 1300
16. Possible answer: Yes; in some cases, the order of operations would matter. For example,
if you simplified 2 (cid:3) 3 (cid:1) 4 by adding first, you would get 20. If you simplified 2 (cid:3) 3 (cid:1) 4 by
multiplying first, you would get 14.
Copyright © by Holt, Rinehart and Winston. 2 Holt Algebra 2
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exploration
1-3 Square Roots
You can use a calculator to help you
investigate some properties of square roots.
To enter square roots, press (cid:18)(cid:78)(cid:68) (cid:18) .
1. Find the value of each expression in the
table. Round to the nearest thousandth.
Expression Value Expression Value
(cid:2) (cid:2) (cid:2)
(cid:3)(cid:3)(cid:3)3 (cid:5) (cid:3)(cid:3)(cid:3)5 3.873 (cid:3)(cid:3)(cid:3)15 3.873
(cid:2) (cid:2) (cid:2)
(cid:3)(cid:3)(cid:3)7 (cid:5) (cid:3)(cid:3)(cid:3)2 3.742 (cid:3)(cid:3)(cid:3)14 3.742
(cid:2) (cid:2) (cid:2)
(cid:3)(cid:3)(cid:3)50 (cid:5) (cid:3)(cid:3)(cid:3)2 10 (cid:3)(cid:3)(cid:3)100 10
2. Based on your answers to Problem 1, what can you say
about (cid:3)(cid:3)(cid:3) (cid:2)a (cid:5) (cid:3)(cid:3)(cid:3)(cid:2)b ? Possible answer: (cid:1)(cid:1)a (cid:4) (cid:1)(cid:1)b (cid:2) (cid:1)(cid:1)ab
3. Find the value of each expression in the table. Round to the
nearest thousandth.
Expression Value Expression Value
(cid:2)
(cid:3)(cid:3)(cid:3)15 (cid:2)
___(cid:2)(cid:2)_ 1.732 (cid:3)(cid:3)(cid:3)3 1.732
(cid:3)(cid:3)(cid:3)5
(cid:2)
(cid:3)(cid:3)(cid:3)60 (cid:2)
____
(cid:2) 2.236 (cid:3)(cid:3)(cid:3)5 2.236
(cid:3)(cid:3)(cid:3)12
(cid:2)
(cid:3)(cid:3)(cid:3)100 (cid:2)
_____
(cid:2) 5 (cid:3)(cid:3)(cid:3)25 5
(cid:3)(cid:3)(cid:3)4
4. Based on your answers to Problem 3, what can you say
(cid:2) (cid:1) (cid:1)
about _ (cid:3)(cid:3)(cid:3)_(cid:2)a_ ? Possible answer: _ (cid:1)_(cid:1)a_ (cid:2) (cid:1) _a
(cid:3)(cid:3)(cid:3)b (cid:1)b b
THINK AND DISCUSS
5. Explain how you can use one of the properties you
(cid:2) (cid:2)
discovered above to simplify (cid:3)(cid:3)(cid:3)5 (cid:5) (cid:3)(cid:3)(cid:3)20 by using mental math.
5. Possible answer: Rewrite the expression as the square root of a product. Then simplify.
(cid:1) (cid:1) (cid:2) (cid:1)
(cid:1)5 · (cid:1)20 (cid:2) (cid:3) 5 · 20 (cid:2) (cid:1) 100 (cid:2) 10
Copyright © by Holt, Rinehart and Winston. 3 Holt Algebra 2
All rights reserved.
exploration
1-3 Square Roots
You can use a calculator to help you
investigate some properties of square roots.
To enter square roots, press (cid:18)(cid:78)(cid:68) (cid:18) .
1. Find the value of each expression in the
table. Round to the nearest thousandth.
Expression Value Expression Value
(cid:2) (cid:2) (cid:2)
(cid:3)(cid:3)(cid:3)3 (cid:5) (cid:3)(cid:3)(cid:3)5 3.873 (cid:3)(cid:3)(cid:3)15 3.873
(cid:2) (cid:2) (cid:2)
(cid:3)(cid:3)(cid:3)7 (cid:5) (cid:3)(cid:3)(cid:3)2 3.742 (cid:3)(cid:3)(cid:3)14 3.742
(cid:2) (cid:2) (cid:2)
(cid:3)(cid:3)(cid:3)50 (cid:5) (cid:3)(cid:3)(cid:3)2 10 (cid:3)(cid:3)(cid:3)100 10
2. Based on your answers to Problem 1, what can you say
about (cid:3)(cid:3)(cid:3) (cid:2)a (cid:5) (cid:3)(cid:3)(cid:3)(cid:2)b ? Possible answer: (cid:1)(cid:1)a (cid:4) (cid:1)(cid:1)b (cid:2) (cid:1)(cid:1)ab
3. Find the value of each expression in the table. Round to the
nearest thousandth.
Expression Value Expression Value
(cid:2)
(cid:3)(cid:3)(cid:3)15 (cid:2)
___(cid:2)(cid:2)_ 1.732 (cid:3)(cid:3)(cid:3)3 1.732
(cid:3)(cid:3)(cid:3)5
(cid:2)
(cid:3)(cid:3)(cid:3)60 (cid:2)
____
(cid:2) 2.236 (cid:3)(cid:3)(cid:3)5 2.236
(cid:3)(cid:3)(cid:3)12
(cid:2)
(cid:3)(cid:3)(cid:3)100 (cid:2)
_____
(cid:2) 5 (cid:3)(cid:3)(cid:3)25 5
(cid:3)(cid:3)(cid:3)4
4. Based on your answers to Problem 3, what can you say
(cid:2) (cid:1) (cid:1)
about _ (cid:3)(cid:3)(cid:3)_(cid:2)a_ ? Possible answer: _ (cid:1)_(cid:1)a_ (cid:2) (cid:1) _a
(cid:3)(cid:3)(cid:3)b (cid:1)b b
THINK AND DISCUSS
5. Explain how you can use one of the properties you
(cid:2) (cid:2)
discovered above to simplify (cid:3)(cid:3)(cid:3)5 (cid:5) (cid:3)(cid:3)(cid:3)20 by using mental math.
5. Possible answer: Rewrite the expression as the square root of a product. Then simplify.
(cid:1) (cid:1) (cid:2) (cid:1)
(cid:1)5 · (cid:1)20 (cid:2) (cid:3) 5 · 20 (cid:2) (cid:1) 100 (cid:2) 10
Copyright © by Holt, Rinehart and Winston. 3 Holt Algebra 2
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exploration
Simplifying Algebraic
1-4
Expressions
Whenever you simplify numerical or algebraic expressions, it is
important to perform the operations in the correct order.
Simplify each expression. In each case, think about the order
in which you should do the operations.
1. (cid:1)7 (cid:1) 2(cid:2)2 (cid:2) 5 76 2. [(cid:1)2 (cid:2) 10(cid:2) (cid:1) (cid:1)4 (cid:2) 1(cid:2)]2 25
3. 3 (cid:2) 5 (cid:1)21 (cid:2) 19(cid:2)3 (cid:5)37 4. [(cid:1)3 3 (cid:2) 1(cid:2) (cid:4) 13 ]2 4
5. Check your answers to Problems 1–4 by entering each
expression into a graphing calculator.
Order of Operations
6. The order of operations tells you the
sequence in which you should perform
1. Parentheses
operations. Fill in the flow chart by
arranging the steps given below in
2. Exponents
the correct order.
(cid:127) Add and subtract from left to right.
3. Multiply and divide
(cid:127) Parentheses
from left to right.
(cid:127) Multiply and divide from left to right.
4.
Add and subtract
(cid:127) Exponents
from left to right.
THINK AND DISCUSS
7. Explain how you can use the order of operations to evaluate
x 2 (cid:2) (cid:1)x (cid:1) y (cid:2) when x (cid:3) (cid:2)3 and y (cid:3) 4.
(cid:2) (cid:1) (cid:1) (cid:2) (cid:2) (cid:1)
8. Discuss whether x y 1 and x y 1 are equivalent
expressions. How does the order of operations determine the
value of the expressions?
7. Possible answer: Substitute (cid:5)3 for x and 4 for y : (cid:2) (cid:5)3 (cid:3) 2 (cid:5) (cid:2) (cid:5)3 (cid:3) 4 (cid:3) . Simplify the
expression in parentheses, then square (cid:5)3, and finally perform the subtraction.
(cid:2) (cid:5)3 (cid:3) 2 (cid:5) (cid:2) (cid:5)3 (cid:3) 4 (cid:3) (cid:2) (cid:2) (cid:5)3 (cid:3) 2 (cid:5) 1 (cid:2) 9 (cid:5) 1 (cid:2) 8
8. No; possible answer: in the first expression, 1 is added to y and then the sum is subtracted
from x. In the second expression, y is subtracted from x and then 1 is added to the difference.
Copyright © by Holt, Rinehart and Winston. 4 Holt Algebra 2
All rights reserved.
exploration
Simplifying Algebraic
1-4
Expressions
Whenever you simplify numerical or algebraic expressions, it is
important to perform the operations in the correct order.
Simplify each expression. In each case, think about the order
in which you should do the operations.
1. (cid:1)7 (cid:1) 2(cid:2)2 (cid:2) 5 76 2. [(cid:1)2 (cid:2) 10(cid:2) (cid:1) (cid:1)4 (cid:2) 1(cid:2)]2 25
3. 3 (cid:2) 5 (cid:1)21 (cid:2) 19(cid:2)3 (cid:5)37 4. [(cid:1)3 3 (cid:2) 1(cid:2) (cid:4) 13 ]2 4
5. Check your answers to Problems 1–4 by entering each
expression into a graphing calculator.
Order of Operations
6. The order of operations tells you the
sequence in which you should perform
1. Parentheses
operations. Fill in the flow chart by
arranging the steps given below in
2. Exponents
the correct order.
(cid:127) Add and subtract from left to right.
3. Multiply and divide
(cid:127) Parentheses
from left to right.
(cid:127) Multiply and divide from left to right.
4.
Add and subtract
(cid:127) Exponents
from left to right.
THINK AND DISCUSS
7. Explain how you can use the order of operations to evaluate
x 2 (cid:2) (cid:1)x (cid:1) y (cid:2) when x (cid:3) (cid:2)3 and y (cid:3) 4.
(cid:2) (cid:1) (cid:1) (cid:2) (cid:2) (cid:1)
8. Discuss whether x y 1 and x y 1 are equivalent
expressions. How does the order of operations determine the
value of the expressions?
7. Possible answer: Substitute (cid:5)3 for x and 4 for y : (cid:2) (cid:5)3 (cid:3) 2 (cid:5) (cid:2) (cid:5)3 (cid:3) 4 (cid:3) . Simplify the
expression in parentheses, then square (cid:5)3, and finally perform the subtraction.
(cid:2) (cid:5)3 (cid:3) 2 (cid:5) (cid:2) (cid:5)3 (cid:3) 4 (cid:3) (cid:2) (cid:2) (cid:5)3 (cid:3) 2 (cid:5) 1 (cid:2) 9 (cid:5) 1 (cid:2) 8
8. No; possible answer: in the first expression, 1 is added to y and then the sum is subtracted
from x. In the second expression, y is subtracted from x and then 1 is added to the difference.
Copyright © by Holt, Rinehart and Winston. 4 Holt Algebra 2
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exploration
1-5 Properties of Exponents
You can use a calculator to help you
investigate some properties of exponents.
Use the key to indicate an exponent.
1. Find the value of each expression in the table.
Expression Value Expression Value
2 2 (cid:5) 2 3 32 25 32
4 3 (cid:5) 4 3 4096 4 6 4096
10 2 (cid:5) 1 0 5 10,000,000 10 7 10,000,000
2. Based on your answers to Problem 1, what can you say
about a m (cid:5) a n? Possible answer: a m (cid:4) a n (cid:2) a m(cid:3)n
3. Find the value of each expression in the table.
Expression Value Expression Value
_ 2_ 5_
8 2 3 8
22
_ 5_ 3_
25 5 2 25
5 1
_1_0_ 6_
1000 10 3 1000
10 3
4. Based on your answers to Problem 3, what can you say
about _ a_ m_? Possible answer: _a m_ (cid:2) a m(cid:5)n
a nn a n
THINK AND DISCUSS
5. Explain how you can use one of the properties you
12 7
_____
discovered above to simplify by using mental math.
126
5. Possible answer: Rewrite the expression as a power of 12 by subtracting
the exponents. Then simplify. _ 1_2_ 7_ (cid:2) 12 7(cid:5)6 (cid:2) 12 1 (cid:2) 12
12 6
Copyright © by Holt, Rinehart and Winston. 5 Holt Algebra 2
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exploration
1-5 Properties of Exponents
You can use a calculator to help you
investigate some properties of exponents.
Use the key to indicate an exponent.
1. Find the value of each expression in the table.
Expression Value Expression Value
2 2 (cid:5) 2 3 32 25 32
4 3 (cid:5) 4 3 4096 4 6 4096
10 2 (cid:5) 1 0 5 10,000,000 10 7 10,000,000
2. Based on your answers to Problem 1, what can you say
about a m (cid:5) a n? Possible answer: a m (cid:4) a n (cid:2) a m(cid:3)n
3. Find the value of each expression in the table.
Expression Value Expression Value
_ 2_ 5_
8 2 3 8
22
_ 5_ 3_
25 5 2 25
5 1
_1_0_ 6_
1000 10 3 1000
10 3
4. Based on your answers to Problem 3, what can you say
about _ a_ m_? Possible answer: _a m_ (cid:2) a m(cid:5)n
a nn a n
THINK AND DISCUSS
5. Explain how you can use one of the properties you
12 7
_____
discovered above to simplify by using mental math.
126
5. Possible answer: Rewrite the expression as a power of 12 by subtracting
the exponents. Then simplify. _ 1_2_ 7_ (cid:2) 12 7(cid:5)6 (cid:2) 12 1 (cid:2) 12
12 6
Copyright © by Holt, Rinehart and Winston. 5 Holt Algebra 2
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