<< Chapter < Page Chapter >> Page >
This module is from Elementary Algebra by Denny Burzynski and Wade Ellis, Jr. Operations with algebraic expressions and numerical evaluations are introduced in this chapter. Coefficients are described rather than merely defined. Special binomial products have both literal and symbolic explanations and since they occur so frequently in mathematics, we have been careful to help the student remember them. In each example problem, the student is "talked" through the symbolic form.Objectives of this module: be able to multiply a polynomial by a monomial, be able to simplify +(a + b) and -(a - b), be able to multiply a polynomial by a polynomial.

Overview

  • Multiplying a Polynomial by a Monomial
  • Simplifying + ( a + b ) and ( a + b )
  • Multiplying a Polynomial by a Polynomial

Multiplying a polynomial by a monomial

Multiplying a polynomial by a monomial is a direct application of the distributive property.

Distributive property

The product of a monomial a and a binomial b plus c is equal to ab plus ac. This is the distributive property. In the expression, there are two arrows originating from the monomial, a, and pointing towards the terms b and c of the binomial.

The distributive property suggests the following rule.

Multiplying a polynomial by a monomial

To multiply a polynomial by a monomial, multiply every term of the polynomial by the monomial and then add the resulting products together.

Sample set a

10 a b 2 c ( 125 a 2 ) = 1250 a 3 b 2 c

Got questions? Get instant answers now!

Practice set a

Determine the following products.

( a 2 2 b + 6 ) 2 a

2 a 3 4 a b + 12 a

Got questions? Get instant answers now!

8 a 2 b 3 ( 2 a + 7 b + 3 )

16 a 3 b 3 + 56 a 2 b 4 + 24 a 2 b 3

Got questions? Get instant answers now!

4 x ( 2 x 5 + 6 x 4 8 x 3 x 2 + 9 x 11 )

8 x 6 + 24 x 5 32 x 4 4 x 3 + 36 x 2 44 x

Got questions? Get instant answers now!

( 3 a 2 b ) ( 2 a b 2 + 4 b 3 )

6 a 3 b 3 + 12 a 2 b 4

Got questions? Get instant answers now!

5 m n ( m 2 n 2 + m + n 0 ) , n 0

5 m 3 n 3 + 5 m 2 n + 5 m n

Got questions? Get instant answers now!

Use a calculator. 6.03 ( 2.11 a 3 + 8.00 a 2 b )

12.7233 a 3 + 48.24 a 2 b

Got questions? Get instant answers now!

Simplifying + ( a + b ) And - ( a + b )

+ ( a + b ) And - ( a + b )

Oftentimes, we will encounter multiplications of the form

+ 1 ( a + b ) or - 1 ( a + b )

These terms will actually appear as

+ ( a + b ) and - ( a + b )

Using the distributive property, we can remove the parentheses.

Removal of a set of parentheses preceded by a plus sign using the distributive property. See the longdesc for a full description.

The parentheses have been removed and the sign of each term has remained the same.

Removal of a set of parentheses preceded by a minus sign using the distributive property. See the longdesc for a full description.

The parentheses have been removed and the sign of each term has been changed to its opposite.

  1. To remove a set of parentheses preceded by a " + " sign, simply remove the parentheses and leave the sign of each term the same.
  2. To remove a set of parentheses preceded by a “ ” sign, remove the parentheses and change the sign of each term to its opposite sign.

Sample set b

Simplify the expressions.

( 6 x 1 ) .

This set of parentheses is preceded by a “ + ’’ sign (implied). We simply drop the parentheses.

( 6 x 1 ) = 6 x 1

Got questions? Get instant answers now!

( 14 a 2 b 3 6 a 3 b 2 + a b 4 ) = 14 a 2 b 3 6 a 3 b 2 + a b 4

Got questions? Get instant answers now!

( 21 a 2 + 7 a 18 ) .

This set of parentheses is preceded by a “ ” sign. We can drop the parentheses as long as we change the sign of every term inside the parentheses to its opposite sign.

( 21 a 2 + 7 a 18 ) = 21 a 2 7 a + 18

Got questions? Get instant answers now!

( 7 y 3 2 y 2 + 9 y + 1 ) = 7 y 3 + 2 y 2 9 y 1

Got questions? Get instant answers now!

Practice set b

Simplify by removing the parentheses.

( a 2 6 a + 10 )

a 2 6 a + 10

Got questions? Get instant answers now!

( x + 2 y )

x 2 y

Got questions? Get instant answers now!

( 5 m 2 n )

5 m + 2 n

Got questions? Get instant answers now!

( 3 s 2 7 s + 9 )

3 s 2 + 7 s 9

Got questions? Get instant answers now!

Multiplying a polynomial by a polynomial

Since we can consider an expression enclosed within parentheses as a single quantity, we have, by the distributive property,

Finding the product of the binomials 'a plus b' and 'c plus d', using the distributive property. See the longdesc for a full description.

For convenience we will use the commutative property of addition to write this expression so that the first two terms contain a and the second two contain b .

Questions & Answers

if three forces F1.f2 .f3 act at a point on a Cartesian plane in the daigram .....so if the question says write down the x and y components ..... I really don't understand
Syamthanda Reply
hey , can you please explain oxidation reaction & redox ?
Boitumelo Reply
hey , can you please explain oxidation reaction and redox ?
Boitumelo
for grade 12 or grade 11?
Sibulele
the value of V1 and V2
Tumelo Reply
advantages of electrons in a circuit
Rethabile Reply
we're do you find electromagnetism past papers
Ntombifuthi
what a normal force
Tholulwazi Reply
it is the force or component of the force that the surface exert on an object incontact with it and which acts perpendicular to the surface
Sihle
what is physics?
Petrus Reply
what is the half reaction of Potassium and chlorine
Anna Reply
how to calculate coefficient of static friction
Lisa Reply
how to calculate static friction
Lisa
How to calculate a current
Tumelo
how to calculate the magnitude of horizontal component of the applied force
Mogano
How to calculate force
Monambi
a structure of a thermocouple used to measure inner temperature
Anna Reply
a fixed gas of a mass is held at standard pressure temperature of 15 degrees Celsius .Calculate the temperature of the gas in Celsius if the pressure is changed to 2×10 to the power 4
Amahle Reply
How is energy being used in bonding?
Raymond Reply
what is acceleration
Syamthanda Reply
a rate of change in velocity of an object whith respect to time
Khuthadzo
how can we find the moment of torque of a circular object
Kidist
Acceleration is a rate of change in velocity.
Justice
t =r×f
Khuthadzo
how to calculate tension by substitution
Precious Reply
hi
Shongi
hi
Leago
use fnet method. how many obects are being calculated ?
Khuthadzo
khuthadzo hii
Hulisani
how to calculate acceleration and tension force
Lungile Reply
you use Fnet equals ma , newtoms second law formula
Masego
please help me with vectors in two dimensions
Mulaudzi Reply
how to calculate normal force
Mulaudzi
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

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. May 08, 2009 Download for free at http://cnx.org/content/col10614/1.3
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