Beginning Algebra, 11th Edition

(Marvins-Underground-K-12) #1
Some students prefer Method 1 for problems like Example 2,which is the
quotient of two fractions. They will use Method 2 for problems like Examples 1,
3, 4, and 5,which have sums or differences in the numerators, or denominators,
or both.

Deciding on a Method and Simplifying Complex Fractions
Simplify each complex fraction.

(a)

Distributive property

Fundamental property

Distributive property

= Combine like terms.

3 y+ 2
y+ 8

=

y+ 2 + 2 y
4 y+ 8 - 3 y

=

11 y+ 22 + 2 y
41 y+ 22 - 3 y

a

1
y
b y 1 y+ 22 +a

2
y+ 2
b y 1 y+ 22

a

4
y
b y 1 y+ 22 - a

3
y+ 2
b y 1 y+ 22

=

a

1
y
+

2
y+ 2
b#y 1 y+ 22

a

4
y





3
y+ 2
b#y 1 y+ 22

=

1
y

+
2
y+ 2
4
y





3
y+ 2

EXAMPLE 6

452 CHAPTER 7 Rational Expressions and Applications


Be careful not to use as the LCD. Because yappears in two denominators, it
must be a factor in the LCD.

y+ 2

There are sums and differences
in the numerator and denominator.
Use Method 2.

Multiply numerator and
denominator by the LCD,
y 1 y+ 22.

(b)

Distributive property

Factor.

= Divide out the common factor.

x+ 1
x- 2

=

1 x- 321 x+ 12
1 x- 321 x- 22

=

x^2 - 2 x- 3
x^2 - 5 x+ 6

a 1 -
2
x


  • 3
    x^2


bx^2

a 1 -
5
x

+
6
x^2

bx^2

=

1 -
2
x


  • 3
    x^2


1 -

5
x
+

6
x^2

There are sums and differences
in the numerator and denominator.
Use Method 2.

Multiply numerator and
denominator by the LCD, x^2.

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