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This module is from Elementary Algebra by Denny Burzynski and Wade Ellis, Jr. This chapter contains many examples of arithmetic techniques that are used directly or indirectly in algebra. Since the chapter is intended as a review, the problem-solving techniques are presented without being developed. Therefore, no work space is provided, nor does the chapter contain all of the pedagogical features of the text. As a review, this chapter can be assigned at the discretion of the instructor and can also be a valuable reference tool for the student.

Overview

  • Prime And Composite Numbers
  • The Fundamental Principle Of Arithmetic
  • The Prime Factorization Of A Whole Number

Prime and composite numbers

Notice that the only factors of 7 are 1 and 7 itself, and that the only factors of 23 are 1 and 23 itself.

Prime number

A whole number greater than 1 whose only whole number factors are itself and 1 is called a prime number.

The first seven prime numbers are

2, 3, 5, 7, 11, 13, and 17

The number 1 is not considered to be a prime number, and the number 2 is the first and only even prime number.
Many numbers have factors other than themselves and 1. For example, the factors of 28 are 1, 2, 4, 7, 14, and 28 (since each of these whole numbers and only these whole numbers divide into 28 without a remainder).

Composite numbers

A whole number that is composed of factors other than itself and 1 is called a composite number. Composite numbers are not prime numbers.

Some composite numbers are 4, 6, 8, 10, 12, and 15.

The fundamental principle of arithmetic

Prime numbers are very important in the study of mathematics. We will use them soon in our study of fractions. We will now, however, be introduced to an important mathematical principle.

The fundamental principle of arithmetic

Except for the order of the factors, every whole number, other than 1, can be factored in one and only one way as a product of prime numbers.

Prime factorization

When a number is factored so that all its factors are prime numbers, the factorization is called the prime factorization of the number.

Sample set a

Find the prime factorization of 10.

10 = 2 · 5

Both 2 and 5 are prime numbers. Thus, 2 · 5 is the prime factorization of 10.

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Find the prime factorization of 60.

60 = 2 · 30 30 is not prime . 30 = 2 · 15 = 2 · 2 · 15 15  is not prime . 15 = 3 · 5 = 2 · 2 · 3 · 5 We'll use exponents .  2 · 2 = 2 2 = 2 2 · 3 · 5

The numbers 2, 3, and 5 are all primes. Thus, 2 2 · 3 · 5 is the prime factorization of 60.

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Find the prime factorization of 11.

11 is a prime number. Prime factorization applies only to composite numbers.

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The prime factorization of a whole number

The following method provides a way of finding the prime factorization of a whole number. The examples that follow will use the method and make it more clear.

  1. Divide the number repeatedly by the smallest prime number that will divide into the number without a remainder.
  2. When the prime number used in step 1 no longer divides into the given number without a remainder, repeat the process with the next largest prime number.
  3. Continue this process until the quotient is 1.
  4. The prime factorization of the given number is the product of all these prime divisors.

Sample set b

Find the prime factorization of 60.

Since 60 is an even number, it is divisible by 2. We will repeatedly divide by 2 until we no longer can (when we start getting a remainder). We shall divide in the following way.

The prime factorization of sixty. See the longdesc for a full description.    30 is divisible by 2 again . 15 is not divisible by 2, but is divisible by 3, the next largest prime . 5 is not divisible by 3, but is divisible by 5, the next largest prime . The quotient is 1 so we stop the division process .

The prime factorization of 60 is the product of all these divisors.

60 = 2 · 2 · 3 · 5 We will use exponents when possible . 60 = 2 2 · 3 · 5

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Find the prime factorization of 441.

Since 441 is an odd number, it is not divisible by 2. We’ll try 3, the next largest prime.

The prime factorization of four hundred forty-one. See the longdesc for a full description.    147 is divisible by 3 . 49 is not divisible by 3 nor by 5 ,  but by 7 . 7 is divisible by 7 . The quotient is 1 so we stop the division process .

The prime factorization of 441 is the product of all the divisors.

441 = 3 · 3 · 7 · 7 We will use exponents when possible . 441 = 3 2 · 7 2

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Exercises

For the following problems, determine which whole numbers are prime and which are composite.

For the following problems, find the prime factorization of each whole number. Use exponents on repeated factors.

819

3 2 · 7 · 13

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148,225

5 2 · 7 2 · 11 2

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Questions & Answers

find the 15th term of the geometric sequince whose first is 18 and last term of 387
Jerwin Reply
I know this work
salma
The given of f(x=x-2. then what is the value of this f(3) 5f(x+1)
virgelyn Reply
hmm well what is the answer
Abhi
how do they get the third part x = (32)5/4
kinnecy Reply
can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
ninjadapaul
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
ninjadapaul
I don't understand what the A with approx sign and the boxed x mean
ninjadapaul
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
ninjadapaul
oops. ignore that.
ninjadapaul
so you not have an equal sign anywhere in the original equation?
ninjadapaul
hmm
Abhi
is it a question of log
Abhi
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salma
Commplementary angles
Idrissa Reply
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Sherica
im all ears I need to learn
Sherica
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Tamia
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Uday
hi
salma
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
Kevin Reply
a perfect square v²+2v+_
Dearan Reply
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Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
Kim
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Al
y=10×
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
how do you translate this in Algebraic Expressions
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Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
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. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
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what's the easiest and fastest way to the synthesize AgNP?
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China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
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Yasmin
what is the function of carbon nanotubes?
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I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
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not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
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Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Elementary algebra. OpenStax CNX. May 08, 2009 Download for free at http://cnx.org/content/col10614/1.3
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