7.1

rational expression
rational function

7.2

least common denominator
(LCD)

7.3

complex fraction

7.4

domain of the variable in a

rational equation

discontinuous

reciprocal function

vertical asymptote

horizontal asymptote

7.5

ratio

proportion

7.6

vary directly

proportional

constant of variation

vary inversely

vary jointly

combined variation

KEY TERMS

1.Arational expressionis
A.an algebraic expression made up
of a term or the sum of a finite
number of terms with real
coefficients and integer
exponents
B.a polynomial equation of
degree 2
C.an expression with one or more
fractions in the numerator,
denominator, or both
D.the quotient of two polynomials
with denominator not 0.

2.In a given set of fractions, the least
common denominatoris
A.the smallest denominator of all
the denominators

B.the smallest expression that is

divisible by all the denominators

C.the largest integer that evenly

divides the numerator and

denominator of all the fractions

D.the largest denominator of all the

denominators.

3.Acomplex fractionis

A.an algebraic expression made up

of a term or the sum of a finite

number of terms with real

coefficients and integer

exponents

B.a polynomial equation of

degree 2

C.an expression with one or more

fractions in the numerator,

denominator, or both

D.the quotient of two polynomials

with denominator not 0.

4.Aratio

A.compares two quantities by using

a quotient

B.says that two quotients are equal

C.is a product of two quantities

D.is a difference between two

quantities.

5.Aproportion

A.compares two quantities by using

a quotient

B.says that two quotients are equal

C.is a product of two quantities

D.is a difference between two

quantities.

TEST YOUR WORD POWER

See how well you have learned the vocabulary in this chapter.

ANSWERS

SUMMARY

CHAPTER 7

1.D;Examples: 2.B;Example:The LCD of and is 3.C;Examples: ,,

4.A;Example: compares two quantities. 5.B;Example:The proportion states that the two ratios are equal.
2
3

8
12

7 in.

12 in.

2

a+ 1

a^2 - 1

x-

1

x

x+^1

y

2

3

4

7

3 x 1 x+ 12.

5

x+ 1

1

x

,

2

3

• ,
  3
  4 y^2
  ,
  5 x^3
  x+ 2
  ,
  a+ 3
  a^2 - 4 a- 5

416 CHAPTER 7 Rational Expressions and Functions