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Beginning and Intermediate Algebra

Sherri Messersmith

Chapter 8

Rational Expressions - all with Video Answers

Educators


Section 1

Simplifying Rational Expressions

01:15

Problem 1

When is a fraction or a rational expression undefined?

Narayan Hari
Narayan Hari
Numerade Educator
00:44

Problem 2

When does a fraction or a rational expression equal $0 ?$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
01:06

Problem 3

Evaluate (if possible) for a) $x=3$ and b) $x=-2$.
$$
\frac{2 x-1}{5 x+2}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:06

Problem 4

Evaluate (if possible) for a) $x=3$ and b) $x=-2$.
$$
\frac{3\left(x^{2}+1\right)}{x^{2}+2 x+1}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:18

Problem 5

Evaluate (if possible) for a) $z=1$ and $\mathrm{b}$ ) $z=-3$.
$$
\frac{(4 z)^{2}}{z^{2}-z-12}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:06

Problem 6

Evaluate (if possible) for a) $z=1$ and $\mathrm{b}$ ) $z=-3$.
$$
\frac{3\left(z^{2}-9\right)}{z^{2}+8}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:01

Problem 7

Evaluate (if possible) for a) $z=1$ and $\mathrm{b}$ ) $z=-3$.
$$
\frac{15+5 z}{16-z^{2}}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:11

Problem 8

Evaluate (if possible) for a) $z=1$ and $\mathrm{b}$ ) $z=-3$.
$$
\frac{4 z-3}{z^{2}+6 z-7}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:07

Problem 9

How do you determine the values of the variable for which a rational expression is undefined?

Narayan Hari
Narayan Hari
Numerade Educator
01:20

Problem 10

If $x^{2}+9$ is the numerator of a rational expression, can that expression equal zero? Give a reason.

Narayan Hari
Narayan Hari
Numerade Educator
01:01

Problem 11

Determine the value(s) of the variable for which
a) the expression equals zero.
b) the expression is undefined.
$$
\frac{m+4}{3 m}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:00

Problem 12

Determine the value(s) of the variable for which
a) the expression equals zero.
b) the expression is undefined.
$$
\frac{-y}{y+3}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:01

Problem 13

Determine the value(s) of the variable for which
a) the expression equals zero.
b) the expression is undefined.
$$
\frac{2 w-7}{4 w+1}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:01

Problem 14

Determine the value(s) of the variable for which
a) the expression equals zero.
b) the expression is undefined.
$$
\frac{3 x+13}{2 x+13}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:09

Problem 15

Determine the value(s) of the variable for which
a) the expression equals zero.
b) the expression is undefined.
$$
\frac{11 v-v^{2}}{5 v-9}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:02

Problem 16

Determine the value(s) of the variable for which
a) the expression equals zero.
b) the expression is undefined.
$$
-\frac{r+5}{r^{2}-100}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:01

Problem 17

Determine the value(s) of the variable for which
a) the expression equals zero.
b) the expression is undefined.
$$
\frac{8}{p}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:01

Problem 18

Determine the value(s) of the variable for which
a) the expression equals zero.
b) the expression is undefined.
$$
\frac{22}{m-1}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:20

Problem 19

Determine the value(s) of the variable for which
a) the expression equals zero.
b) the expression is undefined.
$$
-\frac{7 k}{k^{2}+9 k+20}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:26

Problem 20

Determine the value(s) of the variable for which
a) the expression equals zero.
b) the expression is undefined.
$$
\frac{a-9}{a^{2}+8 a-9}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:26

Problem 21

Determine the value(s) of the variable for which
a) the expression equals zero.
b) the expression is undefined.
$$
\frac{c+20}{2 c^{2}+3 c-9}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:29

Problem 22

Determine the value(s) of the variable for which
a) the expression equals zero.
b) the expression is undefined.
$$
\frac{4}{3 f^{2}-13 f+10}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:09

Problem 23

Determine the value(s) of the variable for which
a) the expression equals zero.
b) the expression is undefined.
$$
\frac{g^{2}+9 g+18}{9 g}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:02

Problem 24

Determine the value(s) of the variable for which
a) the expression equals zero.
b) the expression is undefined.
$$
\frac{6 m-11}{10}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:24

Problem 25

Determine the value(s) of the variable for which
a) the expression equals zero.
b) the expression is undefined.
$$
\frac{4 y}{y^{2}+9}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
01:30

Problem 26

Determine the value(s) of the variable for which
a) the expression equals zero.
b) the expression is undefined.
$$
\frac{q^{2}+49}{7}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:01

Problem 27

Write each rational expression in lowest terms.
$$
\frac{7 x(x-11)}{3(x-11)}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:03

Problem 28

Write each rational expression in lowest terms.
$$
\frac{24(g+3)}{6(g+3)(g-5)}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:06

Problem 29

Write each rational expression in lowest terms.
$$
\frac{24 g^{2}}{56 g^{4}}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:01

Problem 30

Write each rational expression in lowest terms.
$$
\frac{99 d^{7}}{9 d^{3}}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:01

Problem 31

Write each rational expression in lowest terms.
$$
\frac{4 d-20}{5 d-25}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:01

Problem 32

Write each rational expression in lowest terms.
$$
\frac{12 c-3}{8 c-2}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:01

Problem 33

Write each rational expression in lowest terms.
$$
\frac{-14 h-56}{6 h+24}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:02

Problem 34

Write each rational expression in lowest terms.
$$
\frac{-15 v^{2}+12}{40 v^{2}-32}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:03

Problem 35

Write each rational expression in lowest terms.
$$
\frac{39 u^{2}+26}{30 u^{2}+20}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:01

Problem 36

Write each rational expression in lowest terms.
$$
\frac{3 q+15}{-7 q-35}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:02

Problem 37

Write each rational expression in lowest terms.
$$
\frac{g^{2}-g-56}{g+7}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:22

Problem 38

Write each rational expression in lowest terms.
$$
\frac{b^{2}+9 b+20}{b^{2}+b-12}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:01

Problem 39

Write each rational expression in lowest terms.
$$
\frac{t-5}{t^{2}-25}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:06

Problem 40

Write each rational expression in lowest terms.
$$
\frac{r+9}{r^{2}+7 r-18}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:11

Problem 41

Write each rational expression in lowest terms.
$$
\frac{3 c^{2}+28 c+32}{c^{2}+10 c+16}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:09

Problem 42

Write each rational expression in lowest terms.
$$
\frac{6 p^{2}+11 p-10}{9 p^{2}-4}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:17

Problem 43

Write each rational expression in lowest terms.
$$
\frac{q^{2}-25}{2 q^{2}-7 q-15}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:28

Problem 44

Write each rational expression in lowest terms.
$$
\frac{6 p^{2}+11 p-10}{9 p^{2}-4}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:27

Problem 45

Write each rational expression in lowest terms.
$$
\frac{w^{3}+125}{5 w^{2}-25 w+125}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
01:12

Problem 46

Write each rational expression in lowest terms.
$$
\frac{6 w^{3}-48}{w^{2}+2 w+4}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:22

Problem 47

Write each rational expression in lowest terms.
$$
\frac{9 c^{2}-27 c+81}{c^{3}+27}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:01

Problem 48

Write each rational expression in lowest terms.
$$
\frac{4 x+20}{x^{3}+125}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:04

Problem 49

Write each rational expression in lowest terms.
$$
\frac{4 u^{2}-20 u+4 u v-20 v}{13 u+13 v}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:12

Problem 50

Write each rational expression in lowest terms.
$$
\frac{a b+3 a-6 b-18}{b^{2}-9}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:15

Problem 51

Write each rational expression in lowest terms.
$$
\frac{m^{2}-n^{2}}{m^{3}-n^{3}}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:12

Problem 52

Write each rational expression in lowest terms.
$$
\frac{a^{3}+b^{3}}{a^{2}-b^{2}}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
01:01

Problem 53

Any rational expression of the form $\frac{a-b}{b-a}(a \neq b)$ reduces to what?

Narayan Hari
Narayan Hari
Numerade Educator
01:05

Problem 54

Does $\frac{h+4}{h-4}=-1 ?$

Mrinal Rana
Mrinal Rana
Numerade Educator
01:01

Problem 55

Write each rational expression in lowest terms.
$$
\frac{8-q}{q-8}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:01

Problem 56

Write each rational expression in lowest terms.
$$
\frac{m-15}{15-m}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:03

Problem 57

Write each rational expression in lowest terms.
$$
\frac{m^{2}-121}{11-m}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:10

Problem 58

Write each rational expression in lowest terms.
$$
\frac{k-9}{162-2 k^{2}}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:16

Problem 59

Write each rational expression in lowest terms.
$$
\frac{36-42 x}{7 x^{2}+8 x-12}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:04

Problem 60

Write each rational expression in lowest terms.
$$
\frac{a^{2}-6 a-27}{9-a}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:34

Problem 61

Write each rational expression in lowest terms.
$$
\frac{16-4 b^{2}}{b-2}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
01:02

Problem 62

Write each rational expression in lowest terms.
$$
\frac{45-9 v}{v^{2}-25}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:02

Problem 63

Write each rational expression in lowest terms.
$$
\frac{y^{3}-3 y^{2}+2 y-6}{21-7 y}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:52

Problem 64

Write each rational expression in lowest terms.
$$
\frac{8 t^{3}-27}{9-4 t^{2}}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
02:26

Problem 65

Write each rational expression in lowest terms.
$$
\frac{18 c+45}{12 c^{2}+18 c-30}
$$

Mrinal Rana
Mrinal Rana
Numerade Educator
01:01

Problem 66

Write each rational expression in lowest terms.
$$
\frac{36 n^{3}}{42 n^{9}}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:05

Problem 67

Write each rational expression in lowest terms.
$$
\frac{r^{3}-t^{3}}{t^{2}-r^{2}}
$$

Narayan Hari
Narayan Hari
Numerade Educator
00:34

Problem 68

Write each rational expression in lowest terms.
$$
\frac{k^{2}-16 k+64}{k^{3}-8 k^{2}+9 k-72}
$$

Mrinal Rana
Mrinal Rana
Numerade Educator
00:42

Problem 69

Write each rational expression in lowest terms.
$$
\frac{b^{2}+6 b-72}{4 b^{2}+52 b+48}
$$

Mrinal Rana
Mrinal Rana
Numerade Educator
01:26

Problem 70

Write each rational expression in lowest terms.
$$
\frac{5 p^{2}-13 p+6}{32-8 p^{2}}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:01

Problem 71

Write each rational expression in lowest terms.
$$
\frac{28 h^{4}-56 h^{3}+7 h}{7 h}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:48

Problem 72

Write each rational expression in lowest terms.
$$
\frac{z^{2}+5 z-36}{64-z^{3}}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:00

Problem 73

Write each rational expression in lowest terms.
$$
\frac{14-6 w}{12 w^{3}-28 w^{2}}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:01

Problem 74

Write each rational expression in lowest terms.
$$
\frac{54 d^{6}+6 d^{5}-42 d^{3}-18 d^{2}}{6 d^{2}}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:19

Problem 75

Write each rational expression in lowest terms.
$$
\frac{-5 v-10}{v^{3}-v^{2}-4 v+4}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:02

Problem 76

Write each rational expression in lowest terms.
$$
\frac{38 x^{2}+38}{-12 x^{2}-12}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:35

Problem 77

Find three equivalent forms of each rational expression.
$$
-\frac{u+7}{u-2}
$$

Narayan Hari
Narayan Hari
Numerade Educator
00:51

Problem 78

Find three equivalent forms of each rational expression.
$$
-\frac{8 y-1}{2 y+5}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
00:55

Problem 79

Find three equivalent forms of each rational expression.
$$
-\frac{9-5 t}{2 t-3}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
00:43

Problem 80

Find three equivalent forms of each rational expression.
$$
\frac{w-6}{-4 w+7}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
00:50

Problem 81

Find three equivalent forms of each rational expression.
$$
\frac{-12 m}{m^{2}-3}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
02:11

Problem 82

Find three equivalent forms of each rational expression.
$$
\frac{-9 x-11}{18-x}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:54

Problem 83

Reduce to lowest terms
a) using long division.
b) using the methods of this section.
$$
\frac{4 y^{2}-11 y+6}{y-2}
$$

Narayan Hari
Narayan Hari
Numerade Educator
01:10

Problem 84

Reduce to lowest terms
a) using long division.
b) using the methods of this section.
$$
\frac{2 x^{2}+x-28}{x+4}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
02:04

Problem 85

Reduce to lowest terms
a) using long division.
b) using the methods of this section.
$$
\frac{8 a^{3}+125}{2 a+5}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
01:59

Problem 86

Reduce to lowest terms
a) using long division.
b) using the methods of this section.
$$
\frac{27 t^{3}-8}{3 t-2}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
01:08

Problem 87

Recall that the area of a rectangle is $A=l w,$ where $w=$ width and $l=$ length. Solving for the width, we get $w=\frac{A}{l}$ and solving for the length gives us $l=\frac{A}{w}$
Find the missing side in each rectangle.
Find the length.

Narayan Hari
Narayan Hari
Numerade Educator
01:19

Problem 88

Recall that the area of a rectangle is $A=l w,$ where $w=$ width and $l=$ length. Solving for the width, we get $w=\frac{A}{l}$ and solving for the length gives us $l=\frac{A}{w}$
Find the missing side in each rectangle.

Narayan Hari
Narayan Hari
Numerade Educator
01:23

Problem 89

Recall that the area of a rectangle is $A=l w,$ where $w=$ width and $l=$ length. Solving for the width, we get $w=\frac{A}{l}$ and solving for the length gives us $l=\frac{A}{w}$
Find the missing side in each rectangle.

Narayan Hari
Narayan Hari
Numerade Educator
01:04

Problem 90

Recall that the area of a rectangle is $A=l w,$ where $w=$ width and $l=$ length. Solving for the width, we get $w=\frac{A}{l}$ and solving for the length gives us $l=\frac{A}{w}$
Find the missing side in each rectangle.

Narayan Hari
Narayan Hari
Numerade Educator
01:33

Problem 91

Recall that the area of a triangle is $A=\frac{1}{2} b h,$ where $b=$ length of the base and $h=$ height. Solving for the height, we get $h=\frac{2 A}{b}$. Find the height of each triangle.
Area $=3 k^{2}+13 k+4$

Narayan Hari
Narayan Hari
Numerade Educator
01:54

Problem 92

Recall that the area of a triangle is $A=\frac{1}{2} b h,$ where $b=$ length of the base and $h=$ height. Solving for the height, we get $h=\frac{2 A}{b}$. Find the height of each triangle.
Area $=6 p^{2}+52 p+32$

Narayan Hari
Narayan Hari
Numerade Educator
00:57

Problem 93

Determine the domain of each rational function.
$$
f(p)=\frac{1}{p-7}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
00:43

Problem 94

Determine the domain of each rational function.
$$
h(z)=\frac{z+8}{z+3}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
01:21

Problem 95

Determine the domain of each rational function.
$$
k(r)=\frac{r}{5 r+2}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
01:10

Problem 96

Determine the domain of each rational function.
$$
f(a)=\frac{6 a}{7-2 a}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
01:36

Problem 97

Determine the domain of each rational function.
$$
g(t)=\frac{3 t-4}{t^{2}-9 t+8}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
01:33

Problem 98

Determine the domain of each rational function.
$$
r(c)=\frac{c+9}{c^{2}-c-42}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
01:10

Problem 99

Determine the domain of each rational function.
$$
h(w)=\frac{w+7}{w^{2}-81}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
01:20

Problem 100

Determine the domain of each rational function.
$$
k(t)=\frac{t}{t^{2}-14 t+33}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
01:08

Problem 101

Determine the domain of each rational function.
$$
A(c)=\frac{8}{c^{2}+6}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
00:40

Problem 102

Determine the domain of each rational function.
$$
C(n)=\frac{3 n+1}{2}
$$

Sherrie Fenner
Sherrie Fenner
Numerade Educator
01:29

Problem 103

Write your own example of a rational function, $f(x)$, that has a domain of $(-\infty,-8) \cup(-8, \infty)$.

Narayan Hari
Narayan Hari
Numerade Educator
01:37

Problem 104

Write your own example of a rational function, $g(x),$ that has a domain of $(-\infty,-5) \cup(-5,6) \cup(6, \infty)$.

Narayan Hari
Narayan Hari
Numerade Educator