<< Chapter < Page Chapter >> Page >

In the previous set of exercises, you worked with the quadratic equation R = x 2 + 100 x that modeled the revenue received from selling backpacks at a price of x dollars. You found the selling price that would give the maximum revenue and calculated the maximum revenue. Now you will look at more characteristics of this model.
Graph the equation R = x 2 + 100 x . Find the values of the x -intercepts.

Got questions? Get instant answers now!

Writing exercises

For the revenue model in [link] and [link] , explain what the x -intercepts mean to the computer store owner.

Answers will vary.

Got questions? Get instant answers now!

For the revenue model in [link] and [link] , explain what the x -intercepts mean to the backpack retailer.

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 six rows and four columns. The first row is a header row and it labels each column. The first column is labeled

What does this checklist tell you about your mastery of this section? What steps will you take to improve?

10.1 Solve Quadratic Equations Using the Square Root Property

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

m 2 40 = 0

m = ± 2 10

Got questions? Get instant answers now!

r 2 + 32 = 0

no solution

Got questions? Get instant answers now!

4 3 v 2 + 4 = 28

v = ± 3 2

Got questions? Get instant answers now!

5 c 2 + 3 = 19

c = ± 4 5 5

Got questions? Get instant answers now!

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

( p 5 ) 2 + 3 = 19

p = 1 , 9

Got questions? Get instant answers now!

( u + 1 ) 2 = 45

u = −1 ± 3 5

Got questions? Get instant answers now!

( x 1 4 ) 2 = 3 16

x = 1 4 ± 3 4

Got questions? Get instant answers now!

( m 7 ) 2 + 6 = 30

m = 7 ± 2 6

Got questions? Get instant answers now!

( n 4 ) 2 50 = 150

Got questions? Get instant answers now!

( 5 c + 3 ) 2 = −20

no solution

Got questions? Get instant answers now!

m 2 6 m + 9 = 48

m = 3 ± 4 3

Got questions? Get instant answers now!

64 a 2 + 48 a + 9 = 81

a = 3 2 , 3 4

Got questions? Get instant answers now!

4 b 2 28 b + 49 = 25

Got questions? Get instant answers now!

10.2 Solve Quadratic Equations Using Completing the Square

In the following exercises, complete the square to make a perfect square trinomial. Then write the result as a binomial squared.

m 2 8 m

( m 4 ) 2

Got questions? Get instant answers now!

a 2 3 a

( a 3 2 ) 2

Got questions? Get instant answers now!

p 2 + 4 5 p

( p + 2 5 ) 2

Got questions? Get instant answers now!

In the following exercises, solve by completing the square.

c 2 + 20 c = 21

c = 1 , −21

Got questions? Get instant answers now!

x 2 4 x = 32

x = −4 , 8

Got questions? Get instant answers now!

r 2 + 6 r = −100

no solution

Got questions? Get instant answers now!

v 2 14 v = −31

v = 7 ± 3 2

Got questions? Get instant answers now!

m 2 + 10 m 4 = −13

m = −9 , −1

Got questions? Get instant answers now!

a 2 = 3 a + 8

a = 3 2 ± 41 2

Got questions? Get instant answers now!

( u + 8 ) ( u + 4 ) = 14

u = −6 ± 2 2

Got questions? Get instant answers now!

( z 10 ) ( z + 2 ) = 28

Got questions? Get instant answers now!

3 p 2 18 p + 15 = 15

p = 0 , 6

Got questions? Get instant answers now!

4 y 2 6 y = 4

y = 1 2 , 2

Got questions? Get instant answers now!

3 c 2 + 2 c = 9

c = 1 3 ± 2 7 3

Got questions? Get instant answers now!

10.3 Solve Quadratic Equations Using the Quadratic Formula

In the following exercises, solve by using the Quadratic Formula.

4 x 2 5 x + 1 = 0

x = 1 4 , 1

Got questions? Get instant answers now!

r 2 r 42 = 0

r = −6 , 7

Got questions? Get instant answers now!

4 v 2 + v 5 = 0

v = 5 4 , 1

Got questions? Get instant answers now!

3 m 2 + 8 m + 2 = 0

m = −4 ± 10 3

Got questions? Get instant answers now!

6 a 2 5 a + 2 = 0

no real solution

Got questions? Get instant answers now!

u ( u 10 ) + 3 = 0

u = 5 ± 22

Got questions? Get instant answers now!

1 8 p 2 1 5 p = 1 20

p = 4 ± 6 5

Got questions? Get instant answers now!

4 c 2 + 4 c + 1 = 0

c = 1 2

Got questions? Get instant answers now!

In the following exercises, determine the number of solutions to each quadratic equation.

  1. 9 x 2 6 x + 1 = 0
  2. 3 y 2 8 y + 1 = 0
  3. 7 m 2 + 12 m + 4 = 0
  4. 5 n 2 n + 1 = 0

1 2 2 none

Got questions? Get instant answers now!
  1. 5 x 2 7 x 8 = 0
  2. 7 x 2 10 x + 5 = 0
  3. 25 x 2 90 x + 81 = 0
  4. 15 x 2 8 x + 4 = 0
Got questions? Get instant answers now!

In the following exercises, identify the most appropriate method (Factoring, Square Root, or Quadratic Formula) to use to solve each quadratic equation.

  1. 16 r 2 8 r + 1 = 0
  2. 5 t 2 8 t + 3 = 9
  3. 3 ( c + 2 ) 2 = 15

factor Quadratic Formula square root

Got questions? Get instant answers now!
  1. 4 d 2 + 10 d 5 = 21
  2. 25 x 2 60 x + 36 = 0
  3. 6 ( 5 v 7 ) 2 = 150
Got questions? Get instant answers now!

10.4 Solve Applications Modeled by Quadratic Equations

In the following exercises, solve by using methods of factoring, the square root principle, or the quadratic formula.

Find two consecutive odd numbers whose product is 323.

Two consecutive odd numbers whose product is 323 are 17 and 19, and −17 and −19 .

Got questions? Get instant answers now!

Questions & Answers

what is defense mechanism
Chinaza Reply
what is defense mechanisms
Chinaza
I'm interested in biological psychology and cognitive psychology
Tanya Reply
what does preconceived mean
sammie Reply
physiological Psychology
Nwosu Reply
How can I develope my cognitive domain
Amanyire Reply
why is communication effective
Dakolo Reply
Communication is effective because it allows individuals to share ideas, thoughts, and information with others.
effective communication can lead to improved outcomes in various settings, including personal relationships, business environments, and educational settings. By communicating effectively, individuals can negotiate effectively, solve problems collaboratively, and work towards common goals.
it starts up serve and return practice/assessments.it helps find voice talking therapy also assessments through relaxed conversation.
miss
Every time someone flushes a toilet in the apartment building, the person begins to jumb back automatically after hearing the flush, before the water temperature changes. Identify the types of learning, if it is classical conditioning identify the NS, UCS, CS and CR. If it is operant conditioning, identify the type of consequence positive reinforcement, negative reinforcement or punishment
Wekolamo Reply
please i need answer
Wekolamo
because it helps many people around the world to understand how to interact with other people and understand them well, for example at work (job).
Manix Reply
Agreed 👍 There are many parts of our brains and behaviors, we really need to get to know. Blessings for everyone and happy Sunday!
ARC
A child is a member of community not society elucidate ?
JESSY Reply
Isn't practices worldwide, be it psychology, be it science. isn't much just a false belief of control over something the mind cannot truly comprehend?
Simon Reply
compare and contrast skinner's perspective on personality development on freud
namakula Reply
Skinner skipped the whole unconscious phenomenon and rather emphasized on classical conditioning
war
explain how nature and nurture affect the development and later the productivity of an individual.
Amesalu Reply
nature is an hereditary factor while nurture is an environmental factor which constitute an individual personality. so if an individual's parent has a deviant behavior and was also brought up in an deviant environment, observation of the behavior and the inborn trait we make the individual deviant.
Samuel
I am taking this course because I am hoping that I could somehow learn more about my chosen field of interest and due to the fact that being a PsyD really ignites my passion as an individual the more I hope to learn about developing and literally explore the complexity of my critical thinking skills
Zyryn Reply
good👍
Jonathan
and having a good philosophy of the world is like a sandwich and a peanut butter 👍
Jonathan
generally amnesi how long yrs memory loss
Kelu Reply
interpersonal relationships
Abdulfatai Reply
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply
Practice Key Terms 6

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