<< Chapter < Page Chapter >> Page >

Solve: ( 3 r + 4 ) 2 = −8 .

no real solution

Got questions? Get instant answers now!

Solve: ( 2 t 8 ) 2 = −10 .

no real solution

Got questions? Get instant answers now!

The left sides of the equations in the next two examples do not seem to be of the form a ( x h ) 2 . But they are perfect square trinomials, so we will factor to put them in the form we need.

Solve: p 2 10 p + 25 = 18 .

Solution

The left side of the equation is a perfect square trinomial. We will factor it first.

p 2 10 p + 25 = 18 Factor the perfect square trinomial. ( p 5 ) 2 = 18 Use the Square Root Property. p 5 = ± 18 Simplify the radical. p 5 = ± 3 2 Solve for p . p = 5 ± 3 2 Rewrite to show two solutions. p = 5 + 3 2 , p = 5 3 2 Check. We leave the check for you.

Got questions? Get instant answers now!
Got questions? Get instant answers now!

Solve: x 2 6 x + 9 = 12 .

x = 3 + 2 3 , x = 3 2 3

Got questions? Get instant answers now!

Solve: y 2 + 12 y + 36 = 32 .

y = −6 + 4 2 , y = −6 4 2

Got questions? Get instant answers now!

Solve: 4 n 2 + 4 n + 1 = 16 .

Solution

Again, we notice the left side of the equation is a perfect square trinomial. We will factor it first.

4 n 2 + 4 n + 1 = 16
Factor the perfect square trinomial. ( 2 n + 1 ) 2 = 16
Use the Square Root Property. 2 n + 1 = ± 16
Simplify the radical. 2 n + 1 = ± 4
Solve for n . 2 n = 1 ± 4
Divide each side by 2. 2 n 2 = 1 ± 4 2 n = 1 ± 4 2
Rewrite to show two solutions. n = 1 + 4 2 , n = 1 4 2
Simplify each equation. n = 3 2 , n = 5 2
Check.
.
Got questions? Get instant answers now!
Got questions? Get instant answers now!

Solve: 9 m 2 12 m + 4 = 25 .

m = 7 , m = −3

Got questions? Get instant answers now!

Solve: 16 n 2 + 40 n + 25 = 4 .

n = 3 4 , n = 7 4

Got questions? Get instant answers now!

Access these online resources for additional instruction and practice with solving quadratic equations:

Key concepts

  • Square Root Property
    If x 2 = k , and k 0 , then x = k or x = k .

Practice makes perfect

Solve Quadratic Equations of the form a x 2 = k Using the Square Root Property

In the following exercises, solve the following quadratic equations.

r 2 24 = 0

r = ± 2 6

Got questions? Get instant answers now!

u 2 300 = 0

u = ± 10 3

Got questions? Get instant answers now!

x 2 + 20 = 0

no real solution

Got questions? Get instant answers now!

2 5 a 2 + 3 = 11

a = ± 2 5

Got questions? Get instant answers now!

7 p 2 + 10 = 26

p = ± 4 7 7

Got questions? Get instant answers now!

Solve Quadratic Equations of the Form a ( x h ) 2 = k Using the Square Root Property

In the following exercises, solve the following quadratic equations.

( x + 2 ) 2 = 9

x = 1 , x = −5

Got questions? Get instant answers now!

( u 6 ) 2 = 64

u = 14 , u = −2

Got questions? Get instant answers now!

( m 6 ) 2 = 20

m = 6 ± 2 5

Got questions? Get instant answers now!

( r 1 2 ) 2 = 3 4

r = 1 2 ± 3 2

Got questions? Get instant answers now!

( a 7 ) 2 + 5 = 55

a = 7 ± 5 2

Got questions? Get instant answers now!

( b 1 ) 2 9 = 39

Got questions? Get instant answers now!

( 5 c + 1 ) 2 = −27

no real solution

Got questions? Get instant answers now!

m 2 4 m + 4 = 8

m = 2 ± 2 2

Got questions? Get instant answers now!

25 x 2 30 x + 9 = 36

x = 3 5 , x = 9 5

Got questions? Get instant answers now!

Mixed Practice

In the following exercises, solve using the Square Root Property.

( a 4 ) 2 = 28

a = 4 ± 2 7

Got questions? Get instant answers now!

9 w 2 24 w + 16 = 1

w = 1 , w = 5 3

Got questions? Get instant answers now!

a 2 18 = 0

a = ± 3 2

Got questions? Get instant answers now!

( p 1 3 ) 2 = 7 9

p = 1 3 ± 7 3

Got questions? Get instant answers now!

m 2 + 12 = 0

no real solution

Got questions? Get instant answers now!

u 2 14 u + 49 = 72

u = 7 ± 6 2

Got questions? Get instant answers now!

( m 4 ) 2 + 3 = 15

m = 4 ± 2 3

Got questions? Get instant answers now!

( n 7 ) 2 8 = 64

Got questions? Get instant answers now!

( x + 5 ) 2 = 4

x = −3 , x = −7

Got questions? Get instant answers now!

6 c 2 + 4 = 29

c = ± 5 6 6

Got questions? Get instant answers now!

( x 6 ) 2 + 7 = 3

no real solution

Got questions? Get instant answers now!

Everyday math

Paola has enough mulch to cover 48 square feet. She wants to use it to make three square vegetable gardens of equal sizes. Solve the equation 3 s 2 = 48 to find s , the length of each garden side.

4 feet

Got questions? Get instant answers now!

Kathy is drawing up the blueprints for a house she is designing. She wants to have four square windows of equal size in the living room, with a total area of 64 square feet. Solve the equation 4 s 2 = 64 to find s , the length of the sides of the windows.

Got questions? Get instant answers now!

Writing exercises

Explain why the equation x 2 + 12 = 8 has no solution.

Answers will vary.

Got questions? Get instant answers now!

Explain why the equation y 2 + 8 = 12 has two solutions.

Got questions? Get instant answers now!

Self check

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

This table has three rows and four columns. The first row is a header row and it labels each column. The first column is labeled “I can …”, the second “Confidently”, the third “With some help” and the last “No–I don’t get it”. In the “I can…” column the next row reads “solve quadratic equations of the form a x squared equals k using the square root property.” and the last row reads “solve quadratic equations of the form a times the quantity x minus h squared equals k using the square root property.” The remaining columns are blank.

If most of your checks were:

…confidently: Congratulations! You have achieved the objectives in this section. Reflect on the study skills you used so that you can continue to use them. What did you do to become confident of your ability to do these things? Be specific.

…with some help: This must be addressed quickly because topics you do not master become potholes in your road to success. In math, every topic builds upon previous work. It is important to make sure you have a strong foundation before you move on. Who can you ask for help? Your fellow classmates and instructor are good resources. Is there a place on campus where math tutors are available? Can your study skills be improved?

…no-I don’t get it! This is a warning sign and you must not ignore it. You should get help right away or you will quickly be overwhelmed. See your instructor as soon as you can to discuss your situation. Together you can come up with a plan to get you the help you need.

Questions & Answers

differentiate between demand and supply giving examples
Lambiv Reply
differentiated between demand and supply using examples
Lambiv
what is labour ?
Lambiv
how will I do?
Venny Reply
how is the graph works?I don't fully understand
Rezat Reply
information
Eliyee
devaluation
Eliyee
t
WARKISA
hi guys good evening to all
Lambiv
multiple choice question
Aster Reply
appreciation
Eliyee
explain perfect market
Lindiwe Reply
In economics, a perfect market refers to a theoretical construct where all participants have perfect information, goods are homogenous, there are no barriers to entry or exit, and prices are determined solely by supply and demand. It's an idealized model used for analysis,
Ezea
What is ceteris paribus?
Shukri Reply
other things being equal
AI-Robot
When MP₁ becomes negative, TP start to decline. Extuples Suppose that the short-run production function of certain cut-flower firm is given by: Q=4KL-0.6K2 - 0.112 • Where is quantity of cut flower produced, I is labour input and K is fixed capital input (K-5). Determine the average product of lab
Kelo
Extuples Suppose that the short-run production function of certain cut-flower firm is given by: Q=4KL-0.6K2 - 0.112 • Where is quantity of cut flower produced, I is labour input and K is fixed capital input (K-5). Determine the average product of labour (APL) and marginal product of labour (MPL)
Kelo
yes,thank you
Shukri
Can I ask you other question?
Shukri
what is monopoly mean?
Habtamu Reply
What is different between quantity demand and demand?
Shukri Reply
Quantity demanded refers to the specific amount of a good or service that consumers are willing and able to purchase at a give price and within a specific time period. Demand, on the other hand, is a broader concept that encompasses the entire relationship between price and quantity demanded
Ezea
ok
Shukri
how do you save a country economic situation when it's falling apart
Lilia Reply
what is the difference between economic growth and development
Fiker Reply
Economic growth as an increase in the production and consumption of goods and services within an economy.but Economic development as a broader concept that encompasses not only economic growth but also social & human well being.
Shukri
production function means
Jabir
What do you think is more important to focus on when considering inequality ?
Abdisa Reply
any question about economics?
Awais Reply
sir...I just want to ask one question... Define the term contract curve? if you are free please help me to find this answer 🙏
Asui
it is a curve that we get after connecting the pareto optimal combinations of two consumers after their mutually beneficial trade offs
Awais
thank you so much 👍 sir
Asui
In economics, the contract curve refers to the set of points in an Edgeworth box diagram where both parties involved in a trade cannot be made better off without making one of them worse off. It represents the Pareto efficient allocations of goods between two individuals or entities, where neither p
Cornelius
In economics, the contract curve refers to the set of points in an Edgeworth box diagram where both parties involved in a trade cannot be made better off without making one of them worse off. It represents the Pareto efficient allocations of goods between two individuals or entities,
Cornelius
Suppose a consumer consuming two commodities X and Y has The following utility function u=X0.4 Y0.6. If the price of the X and Y are 2 and 3 respectively and income Constraint is birr 50. A,Calculate quantities of x and y which maximize utility. B,Calculate value of Lagrange multiplier. C,Calculate quantities of X and Y consumed with a given price. D,alculate optimum level of output .
Feyisa Reply
Answer
Feyisa
c
Jabir
the market for lemon has 10 potential consumers, each having an individual demand curve p=101-10Qi, where p is price in dollar's per cup and Qi is the number of cups demanded per week by the i th consumer.Find the market demand curve using algebra. Draw an individual demand curve and the market dema
Gsbwnw Reply
suppose the production function is given by ( L, K)=L¼K¾.assuming capital is fixed find APL and MPL. consider the following short run production function:Q=6L²-0.4L³ a) find the value of L that maximizes output b)find the value of L that maximizes marginal product
Abdureman
types of unemployment
Yomi Reply
What is the difference between perfect competition and monopolistic competition?
Mohammed
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply
Practice Key Terms 2

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Elementary algebra. OpenStax CNX. Jan 18, 2017 Download for free at http://cnx.org/content/col12116/1.2
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Elementary algebra' conversation and receive update notifications?

Ask