Beginning Algebra, 11th Edition

(Marvins-Underground-K-12) #1
Simplifying a Complex Fraction (Method 1)
Simplify the complex fraction.

Write both second terms with
a denominator of

Distributive property

Combine like terms.

Multiply by the reciprocal of the
denominator (divisor).

= Divide out the common factor.


  • 5 - 4 x
    4 +x


=


  • 5 - 4 x
    x+ 2


#x+^2
4 +x


  • 5 - 4 x
    x+ 2
    4 +x
    x+ 2


=

3 - 4 x- 8
x+ 2
2 +x+ 2
x+ 2

=

3 - 41 x+ 22
x+ 2
2 + 11 x+ 22
x+ 2

=

x+2.

3
x+ 2





41 x+ 22
x+ 2
2
x+ 2

+

11 x+ 22
x+ 2

=

3
x+ 2


  • 4


2
x+ 2

+ 1

EXAMPLE 3

450 CHAPTER 7 Rational Expressions and Applications


NOW TRY
EXERCISE 3
Simplify the complex
fraction.


5 +
2
a- 3
1
a- 3


  • 2


NOW TRY ANSWER


3.^57 a-- 213 a


Be careful
with signs.

Subtract in the numerator.

Add in the denominator.

NOW TRY

OBJECTIVE 2 Simplify a complex fraction by multiplying numerator and
denominator by the least common denominator (Method 2). Any expression
can be multiplied by a form of 1 to get an equivalent expression. Thus we can multi-
ply both the numerator and the denominator of a complex fraction by the same
nonzero expression to get an equivalent rational expression. If we choose the expres-
sion to be the LCD of all the fractions within the complex fraction, the complex frac-
tion can then be simplified. This is Method 2.

Method 2 for Simplifying a Complex Fraction

Step 1 Find the LCD of all fractions within the complex fraction.


Step 2 Multiply both the numerator and the denominator of the complex


fraction by this LCD using the distributive property as necessary.


Write in lowest terms.


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