<< Chapter < Page Chapter >> Page >

Sample set b

Identify the factors in each term.

9 a 2 6 a 12 contains three terms. Some of the factors in each term are

first term: 9 and a 2 , or , 9 and a and a second term: 6 and a third term: 12 and 1 , or , 12 and 1

Got questions? Get instant answers now!

14 x 5 y + ( a + 3 ) 2 contains two terms. Some of the factors of these terms are

first term: 14 , x 5 , y second term: ( a + 3 ) and ( a + 3 )

Got questions? Get instant answers now!

Practice set b

In the expression 8 x 2 5 x + 6 , list the factors of the
first term:
second term:
third term:

8, x , x ; 5 , x ; 6 and 1 or 3 and 2

Got questions? Get instant answers now!

In the expression 10 + 2 ( b + 6 ) ( b 18 ) 2 , list the factors of the
first term:
second term:

10 and 1 or 5 and 2; 2, b + 6 , b 18 , b 18

Got questions? Get instant answers now!

Common factors

Common factors

Sometimes, when we observe an expression carefully, we will notice that some particular factor appears in every term. When we observe this, we say we are observing common factors . We use the phrase common factors since the particular factor we observe is common to all the terms in the expression. The factor appears in each and every term in the expression.

Sample set c

Name the common factors in each expression.

5 x 3 7 x 3 + 14 x 3 .

The factor x 3 appears in each and every term. The expression x 3 is a common factor.

Got questions? Get instant answers now!

4 x 2 + 7 x .

The factor x appears in each term. The term 4 x 2 is actually 4 x x . Thus, x is a common factor.

Got questions? Get instant answers now!

12 x y 2 9 x y + 15 .

The only factor common to all three terms is the number 3. (Notice that 12 = 3 4 , 9 = 3 3 , 15 = 3 5 .)

Got questions? Get instant answers now!

3 ( x + 5 ) 8 ( x + 5 ) .

The factor ( x + 5 ) appears in each term. So, ( x + 5 ) is a common factor.

Got questions? Get instant answers now!

45 x 3 ( x 7 ) 2 + 15 x 2 ( x 7 ) 20 x 2 ( x 7 ) 5 .

The number 5, the x 2 , and the ( x 7 ) appear in each term. Also, 5 x 2 ( x 7 ) is a factor (since each of the individual quantities is joined by a multiplication sign). Thus, 5 x 2 ( x 7 ) is a common factor.

Got questions? Get instant answers now!

10 x 2 + 9 x 4 .

There is no factor that appears in each and every term. Hence, there are no common factors in this expression.

Got questions? Get instant answers now!

Practice set c

List, if any appear, the common factors in the following expressions.

x 2 + 5 x 2 9 x 2

x 2

Got questions? Get instant answers now!

4 x 2 8 x 3 + 16 x 4 24 x 5

4 x 2

Got questions? Get instant answers now!

4 ( a + 1 ) 3 + 10 ( a + 1 )

2 ( a + 1 )

Got questions? Get instant answers now!

9 a b ( a 8 ) 15 a ( a 8 ) 2

3 a ( a 8 )

Got questions? Get instant answers now!

14 a 2 b 2 c ( c 7 ) ( 2 c + 5 ) + 28 c ( 2 c + 5 )

14 c ( 2 c + 5 )

Got questions? Get instant answers now!

6 ( x 2 y 2 ) + 19 x ( x 2 + y 2 )

no common factor

Got questions? Get instant answers now!

Coefficients

Coefficient

In algebra, as we now know, a letter is often used to represent some quantity. Suppose we represent some quantity by the letter x . The notation 5 x means x + x + x + x + x . We can now see that we have five of these quantities. In the expression 5 x , the number 5 is called the numerical coefficient of the quantity x . Often, the numerical coefficient is just called the coefficient. The coefficient of a quantity records how many of that quantity there are.

Sample set d

12 x means there are 12 x ' s .

Got questions? Get instant answers now!

4 a b means there are four a b ' s .

Got questions? Get instant answers now!

10 ( x 3 ) means there are ten ( x 3 ) ' s .

Got questions? Get instant answers now!

1 y means there is one y . We usually write just y rather than 1 y since it is clear just by looking that there is only one y .

Got questions? Get instant answers now!

7 a 3 means there are seven a 3 ' s .

Got questions? Get instant answers now!

5 a x means there are five a x ' s . It could also mean there are 5 a x ' s . This example shows us that it is important for us to be very clear as to which quantity we are working with. When we see the expression 5 a x we must ask ourselves "Are we working with the quantity a x or the quantity x ?".

Got questions? Get instant answers now!

6 x 2 y 9 means there are six x 2 y 9 ' s . It could also mean there are 6 x 2 y 9 ' s . It could even mean there are 6 y 9 x 2 ' s .

Got questions? Get instant answers now!

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