Elementary Algebra 2e — Original English

Divide Monomials

Simplify Expressions Using the Quotient Property for Exponents

Earlier in this chapter, we developed the properties of exponents for multiplication. We summarize these properties below.

Now we will look at the exponent properties for division. A quick memory refresher may help before we get started. You have learned to simplify fractions by dividing out common factors from the numerator and denominator using the Equivalent Fractions Property. This property will also help you work with algebraic fractions—which are also quotients.

As before, we’ll try to discover a property by looking at some examples.

Step-by-step simplification of rational expressions with exponents using the Equivalent Fractions Property.
Consider x5x2 and x2x3
What do they mean? x·x·x·x·xx·x x·xx·x·x
Use the Equivalent Fractions Property. x·x·x·x·xx·x x·x·1x·x·x
Simplify. x3 1x

Notice, in each case the bases were the same and we subtracted exponents.

When the larger exponent was in the numerator, we were left with factors in the numerator.

When the larger exponent was in the denominator, we were left with factors in the denominator—notice the numerator of 1.

We write:

x5x2x2x3x521x32x31x

This leads to the Quotient Property for Exponents.

A couple of examples with numbers may help to verify this property.

3432=3425253=1532819=3225125=1519=915=15

Simplify: x9x7 31032.

Solution

Solution

To simplify an expression with a quotient, we need to first compare the exponents in the numerator and denominator.


  1. Since 9 > 7, there are more factors of x in the numerator. x to the ninth power divided by x to the seventh power.
    Use the Quotient Property, aman=amn. x to the power of 9 minus 7.
    Simplify. A close-up image shows the mathematical expression 'x squared'.

  2. Since 10 > 2, there are more factors of x in the numerator. 3 to the tenth power divided by 3 squared.
    Use the Quotient Property, aman=amn. 3 to the power of 10 minus 2.
    Simplify. 3 to the eighth power.

    Notice that when the larger exponent is in the numerator, we are left with factors in the numerator.

Simplify: b8b12 7375.

Solution

Solution

To simplify an expression with a quotient, we need to first compare the exponents in the numerator and denominator.


  1. Since 12 > 8, there are more factors of b in the denominator. b to the eighth power divided b to the twelfth power.
    Use the Quotient Property, aman=1anm. 1 divided by b to the power of 12 minus 8.
    Simplify. 1 divided by b to the fourth power.

  2. Since 5 > 3, there are more factors of 3 in the denominator. 7 cubed divided by 7 to the fifth power.
    Use the Quotient Property, aman=1anm. 1 divided by 7 to the power of 5 minus 3.
    Simplify. 1 divided by 7 squared.
    Simplify. The fraction one forty-ninth is displayed, represented as 1 over 49 with a horizontal line separating the numerator and the denominator.

    Notice that when the larger exponent is in the denominator, we are left with factors in the denominator.

Notice the difference in the two previous examples:

  • If we start with more factors in the numerator, we will end up with factors in the numerator.
  • If we start with more factors in the denominator, we will end up with factors in the denominator.


The first step in simplifying an expression using the Quotient Property for Exponents is to determine whether the exponent is larger in the numerator or the denominator.

Simplify: a5a9 x11x7.

Solution

Solution

  1. Is the exponent of a larger in the numerator or denominator? Since 9 > 5, there are more a's in the denominator and so we will end up with factors in the denominator.
    a to the fifth power divided by a to the ninth power.
    Use the Quotient Property, aman=1anm. 1 divided by a to the power of 9 minus 5.
    Simplify. 1 divided by a to the fourth power.
  2. Notice there are more factors of x in the numerator, since 11 > 7. So we will end up with factors in the numerator.
    x to the eleventh power divided by x to the seventh power.
    Use the Quotient Property, aman=1anm. x to the power of 11 minus 7.
    Simplify. x to the fourth power.

Simplify Expressions with an Exponent of Zero

A special case of the Quotient Property is when the exponents of the numerator and denominator are equal, such as an expression like amam. From your earlier work with fractions, you know that:

22=11717=1−43−43=1

In words, a number divided by itself is 1. So, xx=1, for any x(x0), since any number divided by itself is 1.

The Quotient Property for Exponents shows us how to simplify aman when m>n and when n<m by subtracting exponents. What if m=n?

Consider 88, which we know is 1.

This table illustrates the derivation of the zero exponent rule, showing step-by-step how any non-zero number raised to the power of zero equals one.
88=1
Write 8 as 23. 2323=1
Subtract exponents. 233=1
Simplify. 20=1

Now we will simplify amam in two ways to lead us to the definition of the zero exponent. In general, for a0:

This figure is divided into two columns. At the top of the figure, the left and right columns both contain a to the m power divided by a to the m power. In the next row, the left column contains a to the m minus m power. The right column contains the fraction m factors of a divided by m factors of a, represented in the numerator and denominator by a times a followed by an ellipsis. All the as in the numerator and denominator are canceled out. In the bottom row, the left column contains a to the zero power. The right column contains 1.

We see amam simplifies to a0 and to 1. So a0=1.

In this text, we assume any variable that we raise to the zero power is not zero.

Simplify: 90 n0.

Solution

Solution

The definition says any non-zero number raised to the zero power is 1.

This table demonstrates the zero exponent rule with examples, showing that any non-zero base raised to the power of zero equals one.

Use the definition of the zero exponent.
901

Use the definition of the zero exponent.
n01

Now that we have defined the zero exponent, we can expand all the Properties of Exponents to include whole number exponents.

What about raising an expression to the zero power? Let’s look at (2x)0. We can use the product to a power rule to rewrite this expression.

Step-by-step simplification of (2x)^0, illustrating the product to a power rule and zero exponent property.
(2x)0
Use the product to a power rule. 20x0
Use the zero exponent property. 1·1
Simplify. 1

This tells us that any nonzero expression raised to the zero power is one.

Simplify: (5b)0 (−4a2b)0.

Solution

Solution

Examples demonstrating the zero exponent rule, where any non-zero base raised to the power of zero equals one.
(5b)0
Use the definition of the zero exponent. 1
(−4a2b)0
Use the definition of the zero exponent. 1

Simplify Expressions Using the Quotient to a Power Property

Now we will look at an example that will lead us to the Quotient to a Power Property.

Steps demonstrating how to expand and simplify a fraction raised to a power, showing (x/y)^3 equals x^3/y^3.
(xy)3
This means: xy·xy·xy
Multiply the fractions. x·x·xy·y·y
Write with exponents. x3y3

Notice that the exponent applies to both the numerator and the denominator.

Illustration of the power of a quotient rule: (x/y)3 = x3/y3.
We write: (xy)3
x3y3

This leads to the Quotient to a Power Property for Exponents.

An example with numbers may help you understand this property:

(23)3=233323·23·23=827827=827

Simplify: (37)2 (b3)4 (kj)3.

Solution

Solution


3 sevenths squared.
Use the Quotient Property, (ab)m=ambm. 3 squared divided by 7 squared.
Simplify. 9 forty-ninths.


b thirds to the fourth power.
Use the Quotient Property, (ab)m=ambm. b to the fourth power divided by 3 to the fourth power.
Simplify. b to the fourth power divided by 81.


k divided by j, in parentheses, cubed.
Raise the numerator and denominator to the third power. k cubed divided by j cubed.

Simplify Expressions by Applying Several Properties

We’ll now summarize all the properties of exponents so they are all together to refer to as we simplify expressions using several properties. Notice that they are now defined for whole number exponents.

Simplify: (y4)2y6.

Solution

Solution

Steps to simplify the exponential expression (y^4)^2 / y^6 using exponent rules.
(y4)2y6
Multiply the exponents in the numerator. y8y6
Subtract the exponents. y2

Simplify: b12(b2)6.

Solution

Solution

This table illustrates the step-by-step simplification of the exponential expression b^12 / (b^2)^6 using exponent rules, resulting in a final value of 1.
b12(b2)6
Multiply the exponents in the numerator. b12b12
Subtract the exponents. b0
Simplify. 1

Simplify: (y9y4)2.

Solution

Solution

This table demonstrates the step-by-step simplification of the algebraic expression (y^9 / y^4)^2, applying exponent rules for division and power of a power.
(y9y4)2
Remember parentheses come before exponents.
Notice the bases are the same, so we can simplify
inside the parentheses. Subtract the exponents.
(y5)2
Multiply the exponents. y10

Simplify: (j2k3)4.

Solution

Solution

Here we cannot simplify inside the parentheses first, since the bases are not the same.

Step-by-step simplification of a rational expression using the Quotient to a Power Property and other exponent rules.
(j2k3)4
Raise the numerator and denominator to the fourth power
using the Quotient to a Power Property, (ab)m=ambm.
Use the Power Property and simplify. j8k12

Simplify: (2m25n)4.

Solution

Solution

Step-by-step simplification of a rational expression raised to a power using exponent properties.
(2m25n)4
Raise the numberator and denominator to the fourth power,
using the Quotient to a Power Property, (ab)m=ambm.
(2m2)4(5n)4
Raise each factor to the fourth power. (2m2)4(5n)4
Use the Power Property and simplify. 16m8625n4

Simplify: (x3)4(x2)5(x6)5.

Solution

Solution

Step-by-step simplification of an algebraic expression using power and quotient properties of exponents.
(x3)4(x2)5(x6)5
Use the Power Property, (am)n=am·n. (x12)(x10)(x30)
Add the exponents in the numerator. x22x30
Use the Quotient Property, aman=1anm. 1x8

Simplify: (10p3)2(5p)3(2p5)4.

Solution

Solution

Step-by-step simplification of a complex algebraic expression using properties of exponents.
(10p3)2(5p)3(2p5)4
Use the Product to a Power Property, (ab)m=ambm. (10)2(p3)2(5)3(p)3(2)4(p5)4
Use the Power Property, (am)n=am·n. 100p6125p3·16p20
Add the exponents in the denominator. 100p6125·16p23
Use the Quotient Property, aman=1anm. 100125·16p17
Simplify. 120p17

Divide Monomials

You have now been introduced to all the properties of exponents and used them to simplify expressions. Next, you’ll see how to use these properties to divide monomials. Later, you’ll use them to divide polynomials.

Find the quotient: 56x7÷8x3.

Solution

Solution

Steps for simplifying 56x^7 8x^3 to 7x^4, illustrating algebraic division and exponent properties.
56x7÷8x3
Rewrite as a fraction. 56x78x3
Use fraction multiplication. 568x7x3
Simplify and use the Quotient Property. 7x4

Find the quotient: 45a2b3−5ab5.

Solution

Solution

Steps to simplify a rational algebraic expression using fraction multiplication and quotient properties.
45a2b3−5ab5
Use fraction multiplication. 45−5·a2a·b3b5
Simplify and use the Quotient Property. −9·a·1b2
Multiply. 9ab2

Find the quotient: 24a5b348ab4.

Solution

Solution

Step-by-step simplification of an algebraic rational expression using fraction multiplication and quotient properties.
24a5b348ab4
Use fraction multiplication. 2448·a5a·b3b4
Simplify and use the Quotient Property. 12·a4·1b
Multiply. a42b

Once you become familiar with the process and have practiced it step by step several times, you may be able to simplify a fraction in one step.

Find the quotient: 14x7y1221x11y6.

Solution

Solution

Be very careful to simplify 1421 by dividing out a common factor, and to simplify the variables by subtracting their exponents.

This table demonstrates the simplification of a rational expression using the Quotient Property, showing the original expression and its simplified form.
14x7y1221x11y6
Simplify and use the Quotient Property. 2y63x4

In all examples so far, there was no work to do in the numerator or denominator before simplifying the fraction. In the next example, we’ll first find the product of two monomials in the numerator before we simplify the fraction. This follows the order of operations. Remember, a fraction bar is a grouping symbol.

Find the quotient: (6x2y3)(5x3y2)(3x4y5).

Solution

Solution

Step-by-step simplification of a rational algebraic expression.
(6x2y3)(5x3y2)(3x4y5)
Simplify the numerator. 30x5y53x4y5
Simplify. 10x

Key Concepts

  • Quotient Property for Exponents:
    • If a is a real number, a0, and m,n are whole numbers, then:
      aman=amn,m>nandaman=1amn,n>m
  • Zero Exponent
    • If a is a non-zero number, then a0=1.

  • Quotient to a Power Property for Exponents:
    • If a and b are real numbers, b0, and m is a counting number, then:
      (ab)m=ambm
    • To raise a fraction to a power, raise the numerator and denominator to that power.

  • Summary of Exponent Properties
    • If a,b are real numbers and m,n are whole numbers, then
      Product Propertyam·an=am+nPower Property(am)n=am·nProduct to a Power(ab)m=ambmQuotient Propertyaman=amn,a0,m>naman=1anm,a0,n>mZero Exponent Definitionao=1,a0Quotient to a Power Property(ab)m=ambm,b0

Practice Makes Perfect

Simplify Expressions Using the Quotient Property for Exponents

In the following exercises, simplify.

x18x3 51253

y20y10 71672

Solution

y10 714

p21p7 41644

u24u3 91595

Solution

u21 910

q18q36 102103

t10t40 8385

Solution

1t30 164

bb9 446

xx7 10103

Solution

1x6 1100

Simplify Expressions with Zero Exponents

In the following exercises, simplify.

200 b0

130 k0

Solution

1 1

270 (270)

150 (150)

Solution

−1 −1

(25x)0 25x0

(6y)0 6y0

Solution

1 6

(12x)0 (−56p4q3)0

7y0(17y)0 (−93c7d15)0

Solution

7 1

12n018m0 (12n)0(18m)0

15r022s0 (15r)0(22s)0

Solution

−7 0

Simplify Expressions Using the Quotient to a Power Property

In the following exercises, simplify.

(34)3 (p2)5 (xy)6

(25)2 (x3)4 (ab)5

Solution

425 x481 a5b5

(a3b)4 (54m)2

(x2y)3 (103q)4

Solution

x38y3 10,00081q4

Simplify Expressions by Applying Several Properties

In the following exercises, simplify.

(a2)3a4

(p3)4p5

Solution

p7

(y3)4y10

(x4)5x15

Solution

x5

u6(u3)2

v20(v4)5

Solution

1

m12(m8)3

n8(n6)4

Solution

1n16

(p9p3)5

(q8q2)3

Solution

q18

(r2r6)3

(m4m7)4

Solution

1m12

(pr11)2

(ab6)3

Solution

a3b18

(w5x3)8

(y4z10)5

Solution

y20z50

(2j33k)4

(3m55n)3

Solution

27m15125n3

(3c24d6)3

(5u72v3)4

Solution

625u2816v12

(k2k8k3)2

(j2j5j4)3

Solution

j9

(t2)5(t4)2(t3)7

(q3)6(q2)3(q4)8

Solution

1q8

(−2p2)4(3p4)2(−6p3)2

(−2k3)2(6k2)4(9k4)2

Solution

64k6

(−4m3)2(5m4)3(−10m6)3

(−10n2)3(4n5)2(2n8)2

Solution

−4,000

Divide Monomials

In the following exercises, divide the monomials.

56b8÷ 7b2

63v10÷ 9v2

Solution

7v8

−88y15÷ 8y3

−72u12÷ 12u4

Solution

−6u8

45a6b8−15a10b2

54x9y3−18x6y15

Solution

3x3y12

15r4s918r9s2

20m8n430m5n9

Solution

2m33n5

18a4b8−27a9b5

45x5y9−60x8y6

Solution

−3y34x3

64q11r9s348q6r8s5

65a10b8c542a7b6c8

Solution

65a3b242c3

(10m5n4)(5m3n6)25m7n5

(−18p4q7)(−6p3q8)−36p12q10

Solution

−3q5p5

(6a4b3)(4ab5)(12a2b)(a3b)

(4u2v5)(15u3v)(12u3v)(u4v)

Solution

5v4u2

Mixed Practice

24a5+2a5 24a52a5 24a5·2a5 24a5÷2a5

15n10+3n10 15n103n10 15n10·3n10 15n10÷3n10

Solution

18n10 12n10 45n20 5

p4·p6 (p4)6

q5·q3 (q5)3

Solution

q8 q15

y3y yy3

z6z5 z5z6

Solution

z 1z

(8x5)(9x)÷6x3

(4y)(12y7)÷8y2

Solution

6y6

27a73a3+54a99a5

32c114c5+42c96c3

Solution

15c6

32y58y260y105y7

48x66x435x97x7

Solution

3x2

63r6s39r4s272r2s26s

56y4z57y3z345y2z25y

Solution

yz2

Everyday Math

Memory One megabyte is approximately 106 bytes. One gigabyte is approximately 109 bytes. How many megabytes are in one gigabyte?

Memory One gigabyte is approximately 109 bytes. One terabyte is approximately 1012 bytes. How many gigabytes are in one terabyte?

Solution

103

Writing Exercises

Jennifer thinks the quotient a24a6 simplifies to a4. What is wrong with her reasoning?

Maurice simplifies the quotient d7d by writing d7d=7. What is wrong with his reasoning?

Solution

Answers will vary.

When Drake simplified 30 and (−3)0 he got the same answer. Explain how using the Order of Operations correctly gives different answers.

Robert thinks x0 simplifies to 0. What would you say to convince Robert he is wrong?

Solution

Answers will vary.

Self Check

After completing the exercises, use this checklist to evaluate your mastery of the objectives of this section.

This is a table that has six rows and four columns. In the first row, which is a header row, the cells read from left to right “I can…,” “Confidently,” “With some help,” and “No-I don’t get it!” The first column below “I can…” reads “simplify expressions using the Quotient Property for Exponents,” “simplify expressions with zero exponents,” “simplify expressions using the Quotient to a Power Property,” “simplify expressions by applying several properties,” and “divide monomials.” The rest of the cells are blank.

On a scale of 1-10, how would you rate your mastery of this section in light of your responses on the checklist? How can you improve this?