# Connexions

You are here: Home » Content » Elementary Algebra » Algebraic Expressions

• Preface
• Acknowledgments

### Lenses

What is a lens?

#### Definition of a lens

##### Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

##### What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

##### Who can create a lens?

Any individual member, a community, or a respected organization.

##### What are tags?

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

#### Endorsed by (What does "Endorsed by" mean?)

This content has been endorsed by the organizations listed. Click each link for a list of all content endorsed by the organization.
• College Open Textbooks

This collection is included inLens: Community College Open Textbook Collaborative
By: CC Open Textbook Collaborative

"Reviewer's Comments: 'I recommend this book for courses in elementary algebra. The chapters are fairly clear and comprehensible, making them quite readable. The authors do a particularly nice job […]"

Click the "College Open Textbooks" link to see all content they endorse.

Click the tag icon to display tags associated with this content.

#### Affiliated with (What does "Affiliated with" mean?)

This content is either by members of the organizations listed or about topics related to the organizations listed. Click each link to see a list of all content affiliated with the organization.
• OrangeGrove

This collection is included inLens: Florida Orange Grove Textbooks
By: Florida Orange Grove

Click the "OrangeGrove" link to see all content affiliated with them.

Click the tag icon to display tags associated with this content.

• Featured Content

This collection is included inLens: Connexions Featured Content
By: Connexions

"Elementary Algebra covers traditional topics studied in a modern elementary algebra course. Written by Denny Burzynski and Wade Ellis, it is intended for both first-time students and those […]"

Click the "Featured Content" link to see all content affiliated with them.

Click the tag icon to display tags associated with this content.

### Recently Viewed

This feature requires Javascript to be enabled.

### Tags

(What is a tag?)

These tags come from the endorsement, affiliation, and other lenses that include this content.

Inside Collection (Textbook):

Textbook by: Wade Ellis, Denny Burzynski. E-mail the authors

# Algebraic Expressions

Module by: Wade Ellis, Denny Burzynski. E-mail the authors

Summary: This module is from Elementary Algebra by Denny Burzynski and Wade Ellis, Jr. Operations with algebraic expressions and numerical evaluations are introduced in this chapter. Coefficients are described rather than merely defined. Special binomial products have both literal and symbolic explanations and since they occur so frequently in mathematics, we have been careful to help the student remember them. In each example problem, the student is "talked" through the symbolic form. Objectives of this module: be familiar with algebraic expressions, understand the difference between a term and a factor, be familiar with the concept of common factors, know the function of a coefficient.

## Overview

• Algebraic Expressions
• Terms and Factors
• Common Factors
• Coefficients

## Algebraic Expressions

### Algebraic Expression

An algebraic expression is a number, a letter, or a collection of numbers and letters along with meaningful signs of operation.

### Expressions

Algebraic expressions are often referred to simply as expressions, as in the following examples:

### Example 1

x+4 x+4 is an expression.

### Example 2

7y 7y is an expression.

### Example 3

x3 x 2 y 7+9x x3 x 2 y 7+9x is an expression.

### Example 4

The number 8 is an expression. 8 can be written with explicit signs of operation by writing it as 8+0 8+0 or 81 81 .

3 x 2 +6=4x1 3 x 2 +6=4x1 is not an expression, it is an equation. We will study equations in the next section.

## Terms and Factors

### Terms

In an algebraic expression, the quantities joined by "+" "+" signs are called terms.

In some expressions it will appear that terms are joined by "" "" signs. We must keep in mind that subtraction is addition of the negative, that is, ab=a+(b) ab=a+(b) .

An important concept that all students of algebra must be aware of is the difference between terms and factors.

### Factors

Any numbers or symbols that are multiplied together are factors of their product.

Terms are parts of sums and are therefore joined by addition (or subtraction) signs.
Factors are parts of products and are therefore joined by multiplication signs.

## Sample Set A

Identify the terms in the following expressions.

### Example 5

3 x 4 +6 x 2 +5x+8 3 x 4 +6 x 2 +5x+8 .

This expression has four terms: 3 x 4 ,6 x 2 ,5x, 3 x 4 ,6 x 2 ,5x, and 8.

### Example 6

15 y 8 15 y 8 .

In this expression there is only one term. The term is 15 y 8 15 y 8 .

### Example 7

14 x 5 y+ (a+3) 2 14 x 5 y+ (a+3) 2 .

In this expression there are two terms: the terms are 14 x 5 y 14 x 5 y and (a+3) 2 (a+3) 2 . Notice that the term (a+3) 2 (a+3) 2 is itself composed of two like factors, each of which is composed of the two terms, a a and 3.

### Example 8

m 3 3 m 3 3 .

Using our definition of subtraction, this expression can be written in the form m 3 +(3) m 3 +(3) . Now we can see that the terms are m 3 m 3 and 3 3 .

Rather than rewriting the expression when a subtraction occurs, we can identify terms more quickly by associating the + + or - - sign with the individual quantity.

### Example 9

p 4 7 p 3 2p11 p 4 7 p 3 2p11 .

Associating the sign with the individual quantities we see that the terms of this expression are p 4 ,7 p 3 ,2p, p 4 ,7 p 3 ,2p, and 11 11 .

## Practice Set A

### Exercise 1

Let’s say it again. The difference between terms and factors is that terms are joined by


signs and factors are joined by

signs.

List the terms in the following expressions.

### Exercise 2

4 x 2 8x+7 4 x 2 8x+7

### Exercise 3

2xy+6 x 2 + (xy) 4 2xy+6 x 2 + (xy) 4

### Exercise 4

5 x 2 +3x3x y 7 +(xy)( x 3 6) 5 x 2 +3x3x y 7 +(xy)( x 3 6)

## Sample Set B

Identify the factors in each term.

### Example 10

9 a 2 6a12 9 a 2 6a12 contains three terms. Some of the factors in each term are

firstterm: 9and a 2 ,or,9andaanda secondterm: 6anda thirdterm: 12and1,or,12and1 firstterm: 9and a 2 ,or,9andaanda secondterm: 6anda thirdterm: 12and1,or,12and1

### Example 11

14 x 5 y+ (a+3) 2 14 x 5 y+ (a+3) 2 contains two terms. Some of the factors of these terms are

firstterm: 14, x 5 ,y secondterm: (a+3)and(a+3) firstterm: 14, x 5 ,y secondterm: (a+3)and(a+3)

## Practice Set B

### Exercise 5

In the expression 8 x 2 5x+6 8 x 2 5x+6 , list the factors of the
first term:
second term:
third term:

### Exercise 6

In the expression 10+2(b+6) (b18) 2 10+2(b+6) (b18) 2 , list the factors of the
first term:
second term:

## Common Factors

### Common Factors

Sometimes, when we observe an expression carefully, we will notice that some particular factor appears in every term. When we observe this, we say we are observing common factors. We use the phrase common factors since the particular factor we observe is common to all the terms in the expression. The factor appears in each and every term in the expression.

## Sample Set C

Name the common factors in each expression.

### Example 12

5 x 3 7 x 3 +14 x 3 5 x 3 7 x 3 +14 x 3 .

The factor x 3 x 3 appears in each and every term. The expression x 3 x 3 is a common factor.

### Example 13

4 x 2 +7x 4 x 2 +7x .

The factor x x appears in each term. The term 4 x 2 4 x 2 is actually 4xx 4xx . Thus, x x is a common factor.

### Example 14

12x y 2 9xy+15 12x y 2 9xy+15 .

The only factor common to all three terms is the number 3. (Notice that 12=34,9=33,15=35 12=34,9=33,15=35 .)

### Example 15

3(x+5)8(x+5) 3(x+5)8(x+5) .

The factor (x+5) (x+5) appears in each term. So, (x+5) (x+5) is a common factor.

### Example 16

45 x 3 (x7) 2 +15 x 2 (x7)20 x 2 (x7) 5 45 x 3 (x7) 2 +15 x 2 (x7)20 x 2 (x7) 5 .

The number 5, the x 2 x 2 , and the (x7) (x7) appear in each term. Also, 5 x 2 (x7) 5 x 2 (x7) is a factor (since each of the individual quantities is joined by a multiplication sign). Thus, 5 x 2 (x7) 5 x 2 (x7) is a common factor.

### Example 17

10 x 2 +9x4 10 x 2 +9x4 .

There is no factor that appears in each and every term. Hence, there are no common factors in this expression.

## Practice Set C

List, if any appear, the common factors in the following expressions.

### Exercise 7

x 2 +5 x 2 9 x 2 x 2 +5 x 2 9 x 2

### Exercise 8

4 x 2 8 x 3 +16 x 4 24 x 5 4 x 2 8 x 3 +16 x 4 24 x 5

### Exercise 9

4 (a+1) 3 +10(a+1) 4 (a+1) 3 +10(a+1)

### Exercise 10

9ab(a8)15a (a8) 2 9ab(a8)15a (a8) 2

### Exercise 11

14 a 2 b 2 c(c7)(2c+5)+28c(2c+5) 14 a 2 b 2 c(c7)(2c+5)+28c(2c+5)

### Exercise 12

6( x 2 y 2 )+19x( x 2 + y 2 ) 6( x 2 y 2 )+19x( x 2 + y 2 )

## Coefficients

### Coefficient

In algebra, as we now know, a letter is often used to represent some quantity. Suppose we represent some quantity by the letter x x . The notation 5x 5x means x+x+x+x+x x+x+x+x+x . We can now see that we have five of these quantities. In the expression 5x 5x , the number 5 is called the numerical coefficient of the quantity x x . Often, the numerical coefficient is just called the coefficient. The coefficient of a quantity records how many of that quantity there are.

## Sample Set D

### Example 18

12x 12x means there are 12x's 12x's .

### Example 19

4ab 4ab means there are four ab's ab's .

### Example 20

10(x3) 10(x3) means there are ten (x3)'s (x3)'s .

### Example 21

1y 1y means there is one y y . We usually write just y y rather than 1y 1y since it is clear just by looking that there is only one y y .

### Example 22

7 a 3 7 a 3 means there are seven a 3' s a 3' s .

### Example 23

5ax 5ax means there are five ax's ax's . It could also mean there are 5ax's 5ax's . This example shows us that it is important for us to be very clear as to which quantity we are working with. When we see the expression 5ax 5ax we must ask ourselves "Are we working with the quantity ax ax or the quantity x x ?".

### Example 24

6 x 2 y 9 6 x 2 y 9 means there are six x 2 y 9' s x 2 y 9' s . It could also mean there are 6 x 2 y 9' s 6 x 2 y 9' s . It could even mean there are 6 y 9 x 2' s 6 y 9 x 2' s .

### Example 25

5 x 3 (y7) 5 x 3 (y7) means there are five x 3 (y7)'s x 3 (y7)'s . It could also mean there are 5 x 3 (x7)'s 5 x 3 (x7)'s . It could also mean there are 5(x7) x 3 's 5(x7) x 3 's .

## Practice Set D

### Exercise 13

What does the coefficient of a quantity tell us?

#### The Difference Between Coefficients and Exponents

It is important to keep in mind the difference between coefficients and exponents.

Coefficients record the number of like terms in an algebraic expression.
x+x+x+x 4terms = 4x coefficientis4 x+x+x+x 4terms = 4x coefficientis4
Exponents record the number of like factors in a term.
xxxx 4factors = x 4 exponentis4 xxxx 4factors = x 4 exponentis4

In a term, the coefficient of a particular group of factors is the remaining group of factors.

## Sample Set E

### Example 26

3x 3x .

The coefficient of x x is 3.

### Example 27

6 a 3 6 a 3 .

The coefficient of a 3 a 3 is 6.

### Example 28

9(4a) 9(4a) .

The coefficient of (4a) (4a) is 9.

### Example 29

3 8 x y 4 3 8 x y 4 .

The coefficient of x y 4 x y 4 is 3 8 3 8 .

### Example 30

3 x 2 y 3 x 2 y .

The coefficient of x 2 y x 2 y is 3; the coefficient of y y is 3 x 2 3 x 2 ; and the coefficient of 3 is x 2 y x 2 y .

### Example 31

4 (x+y) 2 4 (x+y) 2 .

The coefficient of (x+y) 2 (x+y) 2 is 4; the coefficient of 4 is (x+y) 2 (x+y) 2 ; and the coefficient of (x+y) (x+y) is 4(x+y) 4(x+y) since 4 (x+y) 2 4 (x+y) 2 can be written as 4(x+y)(x+y) 4(x+y)(x+y) .

## Practice Set E

### Exercise 14

Determine the coefficients.
In the term 6 x 3 6 x 3 , the coefficient of
(a) x 3 x 3 is


.
(b) 6 is

.

### Exercise 15

In the term 3x(y1) 3x(y1) , the coefficient of
(a) x(y1) x(y1) is


.
(b) (y1) (y1) is

.
(c) 3(y1) 3(y1) is

.
(d) x x is

.
(e) 3 is

.
(f) The numerical coefficient is

.

### Exercise 16

In the term 10a b 4 10a b 4 , the coefficient of
(a) a b 4 a b 4 is


.
(b) b 4 b 4 is

.
(c) a a is

.
(d) 10 is

.
(e) 10a b 3 10a b 3 is

.

## Exercises

### Exercise 17

What is an algebraic expression?

### Exercise 18

Why is the number 14 considered to be an expression?

### Exercise 19

Why is the number x x considered to be an expression?

For the expressions in the following problems, write the number of terms that appear and then list the terms.

2x+1 2x+1

6x10 6x10

### Exercise 22

2 x 3 +x15 2 x 3 +x15

### Exercise 23

5 x 2 +6x2 5 x 2 +6x2

3x 3x

5cz 5cz

2

61

x x

4 y 3 4 y 3

17a b 2 17a b 2

a+1 a+1

(a+1) (a+1)

2x+x+7 2x+x+7

### Exercise 34

2x+(x+7) 2x+(x+7)

### Exercise 35

(a+1)+(a1) (a+1)+(a1)

### Exercise 36

a+1+(a1) a+1+(a1)

For the following problems, list, if any should appear, the common factors in the expressions.

### Exercise 37

x 2 +5 x 2 2 x 2 x 2 +5 x 2 2 x 2

### Exercise 38

11 y 3 33 y 3 11 y 3 33 y 3

### Exercise 39

45a b 2 +9 b 2 45a b 2 +9 b 2

### Exercise 40

6 x 2 y 3 +18 x 2 6 x 2 y 3 +18 x 2

### Exercise 41

2(a+b)3(a+b) 2(a+b)3(a+b)

### Exercise 42

8 a 2 (b+1)10 a 2 (b+1) 8 a 2 (b+1)10 a 2 (b+1)

### Exercise 43

14a b 2 c 2 (c+8)+12a b 2 c 2 14a b 2 c 2 (c+8)+12a b 2 c 2

### Exercise 44

4 x 2 y+5 a 2 b 4 x 2 y+5 a 2 b

### Exercise 45

9a (a3) 2 +10b(a3) 9a (a3) 2 +10b(a3)

### Exercise 46

15 x 2 30x y 2 15 x 2 30x y 2

### Exercise 47

12 a 3 b 2 c7(b+1)(ca) 12 a 3 b 2 c7(b+1)(ca)

### Exercise 48

0.06a b 2 +0.03a 0.06a b 2 +0.03a

### Exercise 49

5.2 (a+7) 2 +17.1(a+7) 5.2 (a+7) 2 +17.1(a+7)

### Exercise 50

3 4 x 2 y 2 z 2 + 3 8 x 2 z 2 3 4 x 2 y 2 z 2 + 3 8 x 2 z 2

### Exercise 51

9 16 ( a 2 b 2 )+ 9 32 ( b 2 a 2 ) 9 16 ( a 2 b 2 )+ 9 32 ( b 2 a 2 )

For the following problems, note how many:

### Exercise 52

a'sin4a? a'sin4a?

### Exercise 53

z'sin12z? z'sin12z?

### Exercise 54

x 2 'sin5 x 2 ? x 2 'sin5 x 2 ?

### Exercise 55

y 3 'sin6 y 3 ? y 3 'sin6 y 3 ?

### Exercise 56

xy'sin9xy? xy'sin9xy?

### Exercise 57

a 2 b'sin10 a 2 b? a 2 b'sin10 a 2 b?

### Exercise 58

(a+1)'sin4(a+1)? (a+1)'sin4(a+1)?

### Exercise 59

(9+y)'sin8(9+y)? (9+y)'sin8(9+y)?

### Exercise 60

y 2 'sin3 x 3 y 2 ? y 2 'sin3 x 3 y 2 ?

### Exercise 61

12x'sin12 x 2 y 5 ? 12x'sin12 x 2 y 5 ?

### Exercise 62

(a+5)'sin2(a+5)? (a+5)'sin2(a+5)?

### Exercise 63

(xy)'sin5x(xy)? (xy)'sin5x(xy)?

### Exercise 64

(x+1)'sin8(x+1)? (x+1)'sin8(x+1)?

### Exercise 65

2'sin2 x 2 (x7)? 2'sin2 x 2 (x7)?

### Exercise 66

3(a+8)'sin6 x 2 (a+8) 3 (a8)? 3(a+8)'sin6 x 2 (a+8) 3 (a8)?

For the following problems, a term will be given followed by a group of its factors. List the coefficient of the given group of factors.

7y;y 7y;y

10x;x 10x;x

5a;5 5a;5

### Exercise 70

12 a 2 b 3 c 2 r 7 ; a 2 c 2 r 7 12 a 2 b 3 c 2 r 7 ; a 2 c 2 r 7

### Exercise 71

6 x 2 b 2 (c1);c1 6 x 2 b 2 (c1);c1

### Exercise 72

10x (x+7) 2 ;10(x+7) 10x (x+7) 2 ;10(x+7)

### Exercise 73

9 a 2 b 5 ;3a b 3 9 a 2 b 5 ;3a b 3

### Exercise 74

15 x 4 y 4 ( z+9a ) 3 ;( z+9a ) 15 x 4 y 4 ( z+9a ) 3 ;( z+9a )

### Exercise 75

( 4 ) a 6 b 2 ;ab ( 4 ) a 6 b 2 ;ab

### Exercise 76

( 11a ) ( a+8 ) 3 ( a1 ); ( a+8 ) 2 ( 11a ) ( a+8 ) 3 ( a1 ); ( a+8 ) 2

## Exercises for Review

### Exercise 77

((Reference)) Simplify [ 2 x 8 ( x1 ) 5 x 4 ( x1 ) 2 ] 4 [ 2 x 8 ( x1 ) 5 x 4 ( x1 ) 2 ] 4 .

### Exercise 78

((Reference)) Supply the missing phrase. Absolute value speaks to the question of


and not "which way."

### Exercise 79

((Reference)) Find the value of [ 6(42)+7(3+5) ] [ 6(42)+7(3+5) ] .

### Exercise 80

((Reference)) Find the value of 2 5 4 2 3 2 2 5 4 2 3 2 .

### Exercise 81

((Reference)) Express 0.0000152 0.0000152 using scientific notation.

## Content actions

### Give feedback:

#### Collection to:

My Favorites (?)

'My Favorites' is a special kind of lens which you can use to bookmark modules and collections. 'My Favorites' can only be seen by you, and collections saved in 'My Favorites' can remember the last module you were on. You need an account to use 'My Favorites'.

| A lens I own (?)

#### Definition of a lens

##### Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

##### What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

##### Who can create a lens?

Any individual member, a community, or a respected organization.

##### What are tags?

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

| External bookmarks

#### Module to:

My Favorites (?)

'My Favorites' is a special kind of lens which you can use to bookmark modules and collections. 'My Favorites' can only be seen by you, and collections saved in 'My Favorites' can remember the last module you were on. You need an account to use 'My Favorites'.

| A lens I own (?)

#### Definition of a lens

##### Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

##### What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

##### Who can create a lens?

Any individual member, a community, or a respected organization.

##### What are tags?

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

| External bookmarks

### Reuse / Edit:

Reuse or edit collection (?)

#### Check out and edit

If you have permission to edit this content, using the "Reuse / Edit" action will allow you to check the content out into your Personal Workspace or a shared Workgroup and then make your edits.

#### Derive a copy

If you don't have permission to edit the content, you can still use "Reuse / Edit" to adapt the content by creating a derived copy of it and then editing and publishing the copy.

| Reuse or edit module (?)

#### Check out and edit

If you have permission to edit this content, using the "Reuse / Edit" action will allow you to check the content out into your Personal Workspace or a shared Workgroup and then make your edits.

#### Derive a copy

If you don't have permission to edit the content, you can still use "Reuse / Edit" to adapt the content by creating a derived copy of it and then editing and publishing the copy.