# 6.1 Finding the factors of a monomial

 Page 1 / 1
This module is from Elementary Algebra by Denny Burzynski and Wade Ellis, Jr. Factoring is an essential skill for success in algebra and higher level mathematics courses. Therefore, we have taken great care in developing the student's understanding of the factorization process. The technique is consistently illustrated by displaying an empty set of parentheses and describing the thought process used to discover the terms that are to be placed inside the parentheses.The factoring scheme for special products is presented with both verbal and symbolic descriptions, since not all students can interpret symbolic descriptions alone. Two techniques, the standard "trial and error" method, and the "collect and discard" method (a method similar to the "ac" method), are presented for factoring trinomials with leading coefficients different from 1. Objectives of this module: be reminded of products of polynomials, be able to determine a second factor of a polynomial given a first factor.

## Overview

• Products of Polynomials
• Factoring

## Products of polynomials

Previously, we studied multiplication of polynomials (Section [link] ). We were given factors and asked to find their product , as shown below.

Given the factors 4and 8, find the product. $4\cdot 8=32$ . The product is 32.

Given the factors $6{x}^{2}$ and $2x-7$ , find the product.

$6x^{2}\left(2x-7\right)=12x^{3}-42x^{2}$

The product is $12{x}^{3}-42{x}^{2}$ .

Given the factors $x-2y$ and $3x+y$ , find the product.

$\begin{array}{lll}\left(x-2y\right)\left(3x+y\right)\hfill & =\hfill & 3{x}^{2}+xy-6xy-2{y}^{2}\hfill \\ \hfill & =\hfill & 3{x}^{2}-5xy-2{y}^{2}\hfill \end{array}$

The product is $3{x}^{2}-5xy-2{y}^{2}$ .

Given the factors $a+8$ and $a+8$ , find the product.

${\left(a+8\right)}^{2}={a}^{2}+16a+64$

The product is ${a}^{2}+16a+64$ .

## Factoring

Now, let’s reverse the situation. We will be given the product, and we will try to find the factors. This process, which is the reverse of multiplication, is called factoring .

## Factoring

Factoring is the process of determining the factors of a given product.

## Sample set a

The number 24 is the product, and one factor is 6. What is the other factor?

We’re looking for a number $\left(\begin{array}{cc}& \end{array}\right)$ such that $6\cdot \left(\begin{array}{cc}& \end{array}\right)=24$ . We know from experience that $\left(\begin{array}{cc}& \end{array}\right)=4$ . As problems become progressively more complex, our experience may not give us the solution directly. We need a method for finding factors. To develop this method we can use the relatively simple problem $6\cdot \left(\begin{array}{cc}& \end{array}\right)=24$ as a guide.
To find the number $\left(\begin{array}{cc}& \end{array}\right)$ , we would divide 24 by 6.

$\frac{24}{6}=4$

The other factor is 4.

The product is $18{x}^{3}{y}^{4}{z}^{2}$ and one factor is $9x{y}^{2}z$ . What is the other factor?

We know that since $9x{y}^{2}z$ is a factor of $18{x}^{3}{y}^{4}{z}^{2}$ , there must be some quantity $\left(\begin{array}{cc}& \end{array}\right)$ such that $9x{y}^{2}z\cdot \left(\begin{array}{cc}& \end{array}\right)=18{x}^{3}{y}^{4}{z}^{2}$ . Dividing $18{x}^{3}{y}^{4}{z}^{2}$ by $9x{y}^{2}z$ , we get

$\frac{18{x}^{3}{y}^{4}{z}^{2}}{9x{y}^{2}z}=2{x}^{2}{y}^{2}z$

Thus, the other factor is $2{x}^{2}{y}^{2}z$ .

Checking will convince us that $2{x}^{2}{y}^{2}z$ is indeed the proper factor.

$\begin{array}{lll}\left(2{x}^{2}{y}^{2}z\right)\left(9x{y}^{2}z\right)\hfill & =\hfill & 18{x}^{2+1}{y}^{2+2}{z}^{1+1}\hfill \\ \hfill & =\hfill & 18{x}^{3}{y}^{4}{z}^{2}\hfill \end{array}$

We should try to find the quotient mentally and avoid actually writing the division problem.

The product is $-21{a}^{5}{b}^{n}$ and $3a{b}^{4}$ is a factor. Find the other factor.

Mentally dividing $-21{a}^{5}{b}^{n}$ by $3a{b}^{4}$ , we get

$\frac{-21{a}^{5}{b}^{n}}{3a{b}^{4}}=-7{a}^{5-1}{b}^{n-4}=-7{a}^{4}{b}^{n-4}$

Thus, the other factor is $-7{a}^{4}{b}^{n-4}$ .

## Practice set a

The product is 84 and one factor is 6. What is the other factor?

14

The product is $14{x}^{3}{y}^{2}{z}^{5}$ and one factor is $7xyz$ . What is the other factor?

$2{x}^{2}y{z}^{4}$

## Exercises

In the following problems, the first quantity represents the product and the second quantity represents a factor of that product. Find the other factor.

$30,\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}6$

5

$45,\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}9$

$10a,\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}5$

$2a$

$16a,\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}8$

$21b,\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}7b$

3

$15a,\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}5a$

$20{x}^{3},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}4$

$5{x}^{3}$

$30{y}^{4},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}6$

$8{x}^{4},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}4x$

$2{x}^{3}$

$16{y}^{5},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}2y$

$6{x}^{2}y,\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}3x$

$2xy$

$9{a}^{4}{b}^{5},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}9{a}^{4}$

$15{x}^{2}{b}^{4}{c}^{7},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}5{x}^{2}b{c}^{6}$

$3{b}^{3}c$

$25{a}^{3}{b}^{2}c,\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}5ac\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}$

$18{x}^{2}{b}^{5},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}-2x{b}^{4}\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}$

$-9xb$

$22{b}^{8}{c}^{6}{d}^{3},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}-11{b}^{8}{c}^{4}\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}$

$-60{x}^{5}{b}^{3}{f}^{9},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}-15{x}^{2}{b}^{2}{f}^{2}\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}$

$4{x}^{3}b{f}^{7}$

$39{x}^{4}{y}^{5}{z}^{11},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}3x{y}^{3}{z}^{10}\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}$

$147{a}^{20}{b}^{6}{c}^{18}{d}^{2},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}21{a}^{3}bd\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}$

$7{a}^{17}{b}^{5}{c}^{18}d$

$-121{a}^{6}{b}^{8}{c}^{10},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}11{b}^{2}{c}^{5}\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}$

$\frac{1}{8}{x}^{4}{y}^{3},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}\frac{1}{2}x{y}^{3}$

$\frac{1}{4}{x}^{3}$

$7{x}^{2}{y}^{3}{z}^{2},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}7{x}^{2}{y}^{3}z$

$5{a}^{4}{b}^{7}{c}^{3}{d}^{2},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}5{a}^{4}{b}^{7}{c}^{3}d$

$d$

$14{x}^{4}{y}^{3}{z}^{7},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}14{x}^{4}{y}^{3}{z}^{7}$

$12{a}^{3}{b}^{2}{c}^{8},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}12{a}^{3}{b}^{2}{c}^{8}$

1

$6{\left(a+1\right)}^{2}\left(a+5\right),\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}3{\left(a+1\right)}^{2}$

$8{\left(x+y\right)}^{3}\left(x-2y\right),\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}2\left(x-2y\right)$

$4{\left(x+y\right)}^{3}$

$14{\left(a-3\right)}^{6}{\left(a+4\right)}^{2},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}2{\left(a-3\right)}^{2}\left(a+4\right)$

$26{\left(x-5y\right)}^{10}{\left(x-3y\right)}^{12},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}-2{\left(x-5y\right)}^{7}{\left(x-3y\right)}^{7}$

$-13{\left(x-5y\right)}^{3}{\left(x-3y\right)}^{5}$

$34{\left(1-a\right)}^{4}{\left(1+a\right)}^{8},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}-17{\left(1-a\right)}^{4}{\left(1+a\right)}^{2}$

$\left(x+y\right)\left(x-y\right),\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}x-y$

$\left(x+y\right)$

$\left(a+3\right)\left(a-3\right),\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}a-3$

$48{x}^{n+3}{y}^{2n-1},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}8{x}^{3}{y}^{n+5}$

$6{x}^{n}{y}^{n-6}$

$0.0024{x}^{4n}{y}^{3n+5}{z}^{2},\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}0.03{x}^{3n}{y}^{5}$

## Exercises for review

( [link] ) Simplify ${\left({x}^{4}{y}^{0}{z}^{2}\right)}^{3}$ .

${x}^{12}{z}^{6}$

( [link] ) Simplify $-\left\{-\left[-\left(-|6|\right)\right]\right\}$ .

( [link] ) Find the product. ${\left(2x-4\right)}^{2}$ .

$4{x}^{2}-16x+16$

anyone know any internet site where one can find nanotechnology papers?
research.net
kanaga
Introduction about quantum dots in nanotechnology
what does nano mean?
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
it is a goid question and i want to know the answer as well
Maciej
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
for screen printed electrodes ?
SUYASH
What is lattice structure?
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
what's the easiest and fastest way to the synthesize AgNP?
China
Cied
types of nano material
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
how did you get the value of 2000N.What calculations are needed to arrive at it
Privacy Information Security Software Version 1.1a
Good
Berger describes sociologists as concerned with
Please keep in mind that it's not allowed to promote any social groups (whatsapp, facebook, etc...), exchange phone numbers, email addresses or ask for personal information on QuizOver's platform.