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Evaluate 3 x 2 9 x + 7 when

  1. x = 3
  2. x = −1

Solution

x = 3
3 x 2 9 x + 7
Substitute 3 for x 3 ( 3 ) 2 9 ( 3 ) + 7
Simplify the expression with the exponent. 3 · 9 9 ( 3 ) + 7
Multiply. 27 27 + 7
Simplify. 7
x = −1
3 x 2 9 x + 7
Substitute −1 for x 3 ( −1 ) 2 9 ( −1 ) + 7
Simplify the expression with the exponent. 3 · 1 9 ( −1 ) + 7
Multiply. 3 + 9 + 7
Simplify. 19
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Evaluate: 2 x 2 + 4 x 3 when

  1. x = 2
  2. x = −3

  1. 13
  2. 3

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Evaluate: 7 y 2 y 2 when

  1. y = −4
  2. y = 0

  1. 114
  2. −2

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The polynomial −16 t 2 + 300 gives the height of an object t seconds after it is dropped from a 300 foot tall bridge. Find the height after t = 3 seconds.

Solution

.
Substitute 3 for t .
Simplify the expression with the exponent. .
Multiply. .
Simplify. .
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The polynomial −8 t 2 + 24 t + 4 gives the height, in feet, of a ball t seconds after it is tossed into the air, from an initial height of 4 feet. Find the height after t = 3 seconds.

4 feet

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The polynomial −8 t 2 + 24 t + 4 gives the height, in feet, of a ball x seconds after it is tossed into the air, from an initial height of 4 feet. Find the height after t = 2 seconds.

20 feet

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Practice makes perfect

Identify Polynomials, Monomials, Binomials and Trinomials

In the following exercises, determine if each of the polynomials is a monomial, binomial, trinomial, or other polynomial.

a 2 + 9 a + 18

trinomial

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y 3 8 y 2 + 2 y 16

polynomial

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m 4 + 4 m 3 + 6 m 2 + 4 m + 1

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Determine the Degree of Polynomials

In the following exercises, determine the degree of each polynomial.

5 c 3 + 11 c 2 c 8

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Add and Subtract Monomials

In the following exercises, add or subtract the monomials.

Add: 4 a , 3 b , 8 a

−4 a −3 b

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Add: 4 x , 3 y , 3 x

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Subtract 5 x 6 from 12 x 6

−17 x 6

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Subtract 2 p 4 from 7 p 4

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Add and Subtract Polynomials

In the following exercises, add or subtract the polynomials.

( 4 y 2 + 10 y + 3 ) + ( 8 y 2 6 y + 5 )

12 y 2 + 4 y + 8

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( 7 x 2 9 x + 2 ) + ( 6 x 2 4 x + 3 )

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( x 2 + 6 x + 8 ) + ( −4 x 2 + 11 x 9 )

−3 x 2 + 17 x − 1

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( y 2 + 9 y + 4 ) + ( −2 y 2 5 y 1 )

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( 3 a 2 + 7 ) + ( a 2 7 a 18 )

4 a 2 − 7 a − 11

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( p 2 5 p 11 ) + ( 3 p 2 + 9 )

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( 6 m 2 9 m 3 ) ( 2 m 2 + m 5 )

4 m 2 − 10 m + 2

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( 3 n 2 4 n + 1 ) ( 4 n 2 n 2 )

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( z 2 + 8 z + 9 ) ( z 2 3 z + 1 )

11 z + 8

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( z 2 7 z + 5 ) ( z 2 8 z + 6 )

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( 12 s 2 15 s ) ( s 9 )

12 s 2 − 16 s + 9

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( 10 r 2 20 r ) ( r 8 )

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Find the sum of ( 2 p 3 8 ) and ( p 2 + 9 p + 18 )

2 p 3 + p 2 + 9 p + 10

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Find the sum of ( q 2 + 4 q + 13 ) and ( 7 q 3 3 )

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Subtract ( 7 x 2 4 x + 2 ) from ( 8 x 2 x + 6 )

x 2 + 3 x + 4

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Subtract ( 5 x 2 x + 12 ) from ( 9 x 2 6 x 20 )

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Find the difference of ( w 2 + w 42 ) and ( w 2 10 w + 24 )

11 w − 66

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Find the difference of ( z 2 3 z 18 ) and ( z 2 + 5 z 20 )

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Evaluate a Polynomial for a Given Value

In the following exercises, evaluate each polynomial for the given value.

Evaluate 8 y 2 3 y + 2

  1. y = 5
  2. y = −2
  3. y = 0

  1. 187
  2. 40
  3. 2

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Evaluate 5 y 2 y 7 when:

  1. y = −4
  2. y = 1
  3. y = 0

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Evaluate 4 36 x when:

  1. x = 3
  2. x = 0
  3. x = −1

  1. −104
  2. 4
  3. 40

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Evaluate 16 36 x 2 when:

  1. x = −1
  2. x = 0
  3. x = 2

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A window washer drops a squeegee from a platform 275 feet high. The polynomial −16 t 2 + 275 gives the height of the squeegee t seconds after it was dropped. Find the height after t = 4 seconds.

19 feet

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A manufacturer of microwave ovens has found that the revenue received from selling microwaves at a cost of p dollars each is given by the polynomial −5 p 2 + 350 p . Find the revenue received when p = 50 dollars.

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Everyday math

Fuel Efficiency The fuel efficiency (in miles per gallon) of a bus going at a speed of x miles per hour is given by the polynomial 1 160 x 2 + 1 2 x . Find the fuel efficiency when x = 40 mph.

10 mpg

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Stopping Distance The number of feet it takes for a car traveling at x miles per hour to stop on dry, level concrete is given by the polynomial 0.06 x 2 + 1.1 x . Find the stopping distance when x = 60 mph.

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Writing exercises

Using your own words, explain the difference between a monomial, a binomial, and a trinomial.

Answers will vary.

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Eloise thinks the sum 5 x 2 + 3 x 4 is 8 x 6 . What is wrong with her reasoning?

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Self check

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

.

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

how does Neisseria cause meningitis
Nyibol Reply
what is microbiologist
Muhammad Reply
what is errata
Muhammad
is the branch of biology that deals with the study of microorganisms.
Ntefuni Reply
What is microbiology
Mercy Reply
studies of microbes
Louisiaste
when we takee the specimen which lumbar,spin,
Ziyad Reply
How bacteria create energy to survive?
Muhamad Reply
Bacteria doesn't produce energy they are dependent upon their substrate in case of lack of nutrients they are able to make spores which helps them to sustain in harsh environments
_Adnan
But not all bacteria make spores, l mean Eukaryotic cells have Mitochondria which acts as powerhouse for them, since bacteria don't have it, what is the substitution for it?
Muhamad
they make spores
Louisiaste
what is sporadic nd endemic, epidemic
Aminu Reply
the significance of food webs for disease transmission
Abreham
food webs brings about an infection as an individual depends on number of diseased foods or carriers dully.
Mark
explain assimilatory nitrate reduction
Esinniobiwa Reply
Assimilatory nitrate reduction is a process that occurs in some microorganisms, such as bacteria and archaea, in which nitrate (NO3-) is reduced to nitrite (NO2-), and then further reduced to ammonia (NH3).
Elkana
This process is called assimilatory nitrate reduction because the nitrogen that is produced is incorporated in the cells of microorganisms where it can be used in the synthesis of amino acids and other nitrogen products
Elkana
Examples of thermophilic organisms
Shu Reply
Give Examples of thermophilic organisms
Shu
advantages of normal Flora to the host
Micheal Reply
Prevent foreign microbes to the host
Abubakar
they provide healthier benefits to their hosts
ayesha
They are friends to host only when Host immune system is strong and become enemies when the host immune system is weakened . very bad relationship!
Mark
what is cell
faisal Reply
cell is the smallest unit of life
Fauziya
cell is the smallest unit of life
Akanni
ok
Innocent
cell is the structural and functional unit of life
Hasan
is the fundamental units of Life
Musa
what are emergency diseases
Micheal Reply
There are nothing like emergency disease but there are some common medical emergency which can occur simultaneously like Bleeding,heart attack,Breathing difficulties,severe pain heart stock.Hope you will get my point .Have a nice day ❣️
_Adnan
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Innocent
I think infection prevention and control is the avoidance of all things we do that gives out break of infections and promotion of health practices that promote life
Lubega
Heyy Lubega hussein where are u from?
_Adnan
en français
Adama
which site have a normal flora
ESTHER Reply
Many sites of the body have it Skin Nasal cavity Oral cavity Gastro intestinal tract
Safaa
skin
Asiina
skin,Oral,Nasal,GIt
Sadik
How can Commensal can Bacteria change into pathogen?
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How can Commensal Bacteria change into pathogen?
Sadik
all
Tesfaye
by fussion
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what are the advantages of normal Flora to the host
Micheal
what are the ways of control and prevention of nosocomial infection in the hospital
Micheal
what is inflammation
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part of a tissue or an organ being wounded or bruised.
Wilfred
what term is used to name and classify microorganisms?
Micheal Reply
Binomial nomenclature
adeolu
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Practice Key Terms 7

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Source:  OpenStax, Prealgebra. OpenStax CNX. Jul 15, 2016 Download for free at http://legacy.cnx.org/content/col11756/1.9
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