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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