answers (lesson 3-1) · a system of equations is a set of two or more equations containing the same...

19
Chapter 3 A1 Glencoe Algebra 2 Answers STEP 1 Chapter 3 3 Glencoe Algebra 2 NAME ______________________________________________ DATE______________ PERIOD _____ 3 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Anticipation Guide Systems of Equations and Inequalities Chapter Resources Before you begin Chapter 3 Read each statement. Decide whether you Agree (A) or Disagree (D) with the statement. Write A or D in the first column OR if you are not sure whether you agree or disagree, write NS (Not Sure). After you complete Chapter 3 Reread each statement and complete the last column by entering an A or a D. Did any of your opinions about the statements change from the first column? For those statements that you mark with a D, use a piece of paper to write an example of why you disagree. STEP 2 STEP 1 STEP 2 A, D, or NS Statement A or D 1. A system of equations consists of two or more equations with different variables. D 2. The solution of a system of equations can be found by finding the intersection of the graphs of the equations. A 3. A system of equations that is inconsistent has an infinite number of solutions. D 4. Given the two equations y x 7 and 3x 4y 10, a solution can be found by substituting x 7 for y in the A second equation. 5. The product of the equation 6m 4n 22 and 2 is 12m 8n 22. D 6. When solving a system of inequalities by graphing, if the graphs do not intersect then there is no solution. A 7. All the ordered pairs in the intersection of the graphs of a system of inequalities are called constraints. D 8. If the intersection of the graphs of a system of inequalities is a polygonal region, that region is called bounded. A 9. Linear programming is the process of finding all solutions to a system of linear inequalities. D 10. The solution to a system of equations with three variables is written as (x, y, z) and is called an ordered triple. A Lesson 3-1 Chapter 3 5 Glencoe Algebra 2 NAME ______________________________________________ DATE______________ PERIOD _____ 3-1 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Lesson Reading Guide Solving Systems of Equations by Graphing Get Ready for the Lesson Read the introduction to Lesson 3-1 in your textbook. Which are growing faster, in-store sales or online sales? online sales In what year is the in-store and online sales the same? 2005 Read the Lesson 1. The Study Tip on page 117 of your textbook says that when you solve a system of equations by graphing and find a point of intersection of the two lines, you must always check the ordered pair in both of the original equations. Why is it not good enough to check the ordered pair in just one of the equations? Sample answer:To be a solution of the system, the ordered pair must make both of the equations true. 2. Under each system graphed below, write all of the following words that apply: consistent, inconsistent, dependent, and independent. inconsistent consistent; consistent; dependent independent Remember What You Learned 3. Look up the words consistent and inconsistent in a dictionary. How can the meaning of these words help you distinguish between consistent and inconsistent systems of equations? Sample answer: One meaning of consistent is “being in agreement,” or “compatible,” while one meaning of inconsistent is “not being in agreement” or “incompatible.”When a system is consistent, the equations are compatible because both can be true at the same time (for the same values of x and y). When a system is inconsistent, the equations are incompatible because they can never be true at the same time. x y O x y O x y O Answers (Lesson 3-1)

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Page 1: Answers (Lesson 3-1) · A system of equations is a set of two or more equations containing the same variables. You can solve a system of linear equations by graphing the equations

Chapter 3 A1 Glencoe Algebra 2

An

swer

s

STEP

1

Cha

pter

33

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3

Copyright ©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Ant

icip

atio

n G

uide

Sys

tem

s o

f E

qu

atio

ns

and

Ineq

ual

itie

s

Chapter Resources

Bef

ore

you

beg

in C

ha

pte

r 3

•R

ead

each

sta

tem

ent.

•D

ecid

e w

het

her

you

Agr

ee (

A)

or D

isag

ree

(D)

wit

h t

he

stat

emen

t.

•W

rite

A o

r D

in

th

e fi

rst

colu

mn

OR

if

you

are

not

su

re w

het

her

you

agr

ee o

r di

sagr

ee,

wri

te N

S (

Not

Su

re).

Aft

er y

ou c

omp

lete

Ch

ap

ter

3

•R

erea

d ea

ch s

tate

men

t an

d co

mpl

ete

the

last

col

um

n b

y en

teri

ng

an A

or

a D

.

•D

id a

ny

of y

our

opin

ion

s ab

out

the

stat

emen

ts c

han

ge f

rom

th

e fi

rst

colu

mn

?

•F

or t

hos

e st

atem

ents

th

at y

ou m

ark

wit

h a

D,u

se a

pie

ce o

f pa

per

to w

rite

an

exa

mpl

e of

wh

y yo

u d

isag

ree.

STEP

2

ST

EP

1S

TE

P 2

A,D

,or

NS

Sta

tem

ent

A o

r D

1.A

sys

tem

of

equ

atio

ns

con

sist

s of

tw

o or

mor

e eq

uat

ion

s w

ith

di

ffer

ent

vari

able

s.D

2.T

he

solu

tion

of

a sy

stem

of

equ

atio

ns

can

be

fou

nd

by f

indi

ng

the

inte

rsec

tion

of

the

grap

hs

of t

he

equ

atio

ns.

A

3.A

sys

tem

of

equ

atio

ns

that

is

inco

nsi

sten

t h

as a

n i

nfi

nit

e n

um

ber

of s

olu

tion

s.D

4.G

iven

th

e tw

o eq

uat

ion

s y

�x

�7

and

3x�

4y�

10,a

so

luti

on c

an b

e fo

un

d by

su

bsti

tuti

ng

x�

7 fo

r y

in t

he

Ase

con

d eq

uat

ion

.

5.T

he

prod

uct

of

the

equ

atio

n 6

m�

4n�

22 a

nd

�2

is �

12m

�8n

�22

.D

6.W

hen

sol

vin

g a

syst

em o

f in

equ

alit

ies

by g

raph

ing,

if t

he

grap

hs

do n

ot i

nte

rsec

t th

en t

her

e is

no

solu

tion

.A

7.A

ll t

he

orde

red

pair

s in

th

e in

ters

ecti

on o

f th

e gr

aph

s of

a

syst

em o

f in

equ

alit

ies

are

call

ed c

onst

rain

ts.

D

8.If

th

e in

ters

ecti

on o

f th

e gr

aph

s of

a s

yste

m o

f in

equ

alit

ies

is

a po

lygo

nal

reg

ion

,th

at r

egio

n i

s ca

lled

bou

nde

d.A

9.Li

nea

r pr

ogra

mm

ing

is t

he

proc

ess

of f

indi

ng

all

solu

tion

s to

a

syst

em o

f li

nea

r in

equ

alit

ies.

D

10.

Th

e so

luti

on t

o a

syst

em o

f eq

uat

ion

s w

ith

th

ree

vari

able

s is

w

ritt

en a

s (x

,y,z

) an

d is

cal

led

an o

rder

ed t

ripl

e.A

Lesson 3-1

Cha

pter

35

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-1

Copyright ©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Less

on R

eadi

ng G

uide

So

lvin

g S

yste

ms

of

Eq

uat

ion

s by

Gra

ph

ing

Get

Rea

dy

for

the

Less

on

Rea

d t

he

intr

odu

ctio

n t

o L

esso

n 3

-1 i

n y

our

text

boo

k.

•W

hic

h a

re g

row

ing

fast

er,i

n-s

tore

sal

es o

r on

lin

e sa

les?

on

line

sale

s

•In

wh

at y

ear

is t

he

in-s

tore

an

d on

lin

e sa

les

the

sam

e?20

05

Rea

d t

he

Less

on

1.T

he

Stu

dy T

ip o

n p

age

117

of y

our

text

book

say

s th

at w

hen

you

sol

ve a

sys

tem

of

equ

atio

ns

by g

raph

ing

and

fin

d a

poin

t of

in

ters

ecti

on o

f th

e tw

o li

nes

,you

mu

st a

lway

sch

eck

the

orde

red

pair

in

bot

hof

th

e or

igin

al e

quat

ion

s.W

hy

is i

t n

ot g

ood

enou

gh t

och

eck

the

orde

red

pair

in

just

on

e of

th

e eq

uat

ion

s?S

amp

le a

nsw

er:T

o b

e a

solu

tio

n o

f th

e sy

stem

,th

e o

rder

ed p

air

mu

stm

ake

bo

th o

f th

e eq

uat

ion

s tr

ue.

2.U

nde

r ea

ch s

yste

m g

raph

ed b

elow

,wri

te a

ll o

f th

e fo

llow

ing

wor

ds t

hat

app

ly:c

onsi

sten

t,in

con

sist

ent,

dep

end

ent,

and

ind

epen

den

t.

inco

nsi

sten

tco

nsi

sten

t;co

nsi

sten

t;d

epen

den

tin

dep

end

ent

Rem

emb

er W

hat

Yo

u L

earn

ed

3.L

ook

up

the

wor

ds c

onsi

sten

tan

d in

con

sist

ent

in a

dic

tion

ary.

How

can

th

e m

ean

ing

ofth

ese

wor

ds h

elp

you

dis

tin

guis

h b

etw

een

con

sist

ent

and

inco

nsi

sten

t sy

stem

s of

equ

atio

ns?

Sam

ple

an

swer

:O

ne

mea

nin

g o

f co

nsi

sten

tis

“b

ein

g in

ag

reem

ent,”

or

“co

mp

atib

le,”

wh

ile o

ne

mea

nin

g o

f in

con

sist

ent

is “

no

t b

ein

g in

agre

emen

t”o

r “i

nco

mp

atib

le.”

Wh

en a

sys

tem

is c

on

sist

ent,

the

equ

atio

ns

are

com

pat

ible

bec

ause

bo

th c

an b

e tr

ue

at t

he

sam

e ti

me

(fo

rth

e sa

me

valu

es o

f x

and

y).

Wh

en a

sys

tem

is in

con

sist

ent,

the

equ

atio

ns

are

inco

mp

atib

le b

ecau

se t

hey

can

nev

er b

e tr

ue

at t

he

sam

e ti

me.

x

y

Ox

y

Ox

y

O

Answers (Lesson 3-1)

A1-A19 A2-03-873973 5/22/06 8:25 AM Page A1

Page 2: Answers (Lesson 3-1) · A system of equations is a set of two or more equations containing the same variables. You can solve a system of linear equations by graphing the equations

Chapter 3 A2 Glencoe Algebra 2

Cha

pter

36

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Stud

y G

uide

and

Inte

rven

tion

So

lvin

g S

yste

ms

of

Eq

uat

ion

s by

Gra

ph

ing

Gra

ph

Sys

tem

s o

f Eq

uat

ion

sA

sys

tem

of

equ

atio

ns

is a

set

of

two

or m

ore

equ

atio

ns

con

tain

ing

the

sam

e va

riab

les.

You

can

sol

ve a

sys

tem

of

lin

ear

equ

atio

ns

bygr

aph

ing

the

equ

atio

ns

on t

he

sam

e co

ordi

nat

e pl

ane.

If t

he

lin

es i

nte

rsec

t,th

e so

luti

on i

sth

at i

nte

rsec

tion

poi

nt.

Sol

ve t

he

syst

em o

f eq

uat

ion

s b

y gr

aph

ing.

x �

2y�

4x

�y

��

2W

rite

eac

h e

quat

ion

in

slo

pe-i

nte

rcep

t fo

rm.

x �

2y�

4→

y�

�2

x�

y�

�2

→y

��

x�

2

Th

e gr

aph

s ap

pear

to

inte

rsec

t at

(0,

�2)

.

CH

ECK

Su

bsti

tute

th

e co

ordi

nat

es i

nto

eac

h e

quat

ion

.x

�2y

�4

x�

y�

�2

0 �

2(�

2) �

40

�(�

2)�

�2

4 �

4✓

�2

��

2✓

Th

e so

luti

on o

f th

e sy

stem

is

(0,�

2).

Sol

ve e

ach

sys

tem

of

equ

atio

ns

by

grap

hin

g.

1.y

��

�1

2.y

�2x

�2

3.y

��

�3

y�

�4

(6,�

1)y

��

x�

4(2

,2)

y�

(4,1

)

4.3x

�y

�0

5.2x

��

�7

6.�

y�

2

x�

y�

�2

(1,3

)�

y�

1(�

4,3)

2x�

y�

�1

(�2,

�3)

( –2,

–3)

x

y

O

( –4,

3)

x

y

O

( 1, 3

)

x

y

O

x � 2

x � 2y � 3

( 4, 1

)

x

y

O

( 2, 2

)

x

y

O

( 6, –

1)

x

y

O

x � 4x � 2

x � 2x � 3

x

y

O

( 0, –

2)

x � 2

Exam

ple

Exer

cise

s

Lesson 3-1

Cha

pter

37

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-1

Copyright ©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Cla

ssif

y Sy

stem

s o

f Eq

uat

ion

sT

he

foll

owin

g ch

art

sum

mar

izes

th

e po

ssib

ilit

ies

for

grap

hs

of t

wo

lin

ear

equ

atio

ns

in t

wo

vari

able

s.

Gra

ph

s o

f E

qu

atio

ns

Slo

pes

of

Lin

esC

lass

ific

atio

n o

f S

yste

mN

um

ber

of

So

luti

on

s

Line

s in

ters

ect

Diff

eren

t sl

opes

Con

sist

ent

and

inde

pend

ent

One

Line

s co

inci

de (

sam

e lin

e)S

ame

slop

e, s

ame

Con

sist

ent

and

depe

nden

tIn

finite

ly m

any

y-in

terc

ept

Line

s ar

e pa

ralle

lS

ame

slop

e, d

iffer

ent

Inco

nsis

tent

Non

e y-

inte

rcep

ts

Gra

ph

th

e sy

stem

of

equ

atio

ns

x�

3y�

6an

d d

escr

ibe

it a

s co

nsi

sten

t a

nd

in

dep

end

ent,

2x�

y�

�3

con

sist

ent

an

d d

epen

den

t,or

in

con

sist

ent.

Wri

te e

ach

equ

atio

n i

n s

lope

-in

terc

ept

form

.

x�

3y�

6→

y�

x�

2

2x�

y�

�3

→y

�2x

�3

Th

e gr

aph

s in

ters

ect

at (

�3,

�3)

.Sin

ce t

her

e is

on

e so

luti

on,t

he

syst

em i

s co

nsi

sten

t an

d in

depe

nde

nt.

Gra

ph

th

e sy

stem

of

equ

atio

ns

and

des

crib

e it

as

con

sist

ent

an

d i

nd

epen

den

t,co

nsi

sten

t a

nd

dep

end

ent,

or i

nco

nsi

sten

t.

1.3x

�y

��

2 2.

x�

2y�

5 3.

2x�

3y�

06x

�2y

�10

3x�

15 �

�6y

co

nsi

sten

t4x

�6y

�3

inco

nsi

sten

tan

d d

epen

den

tin

con

sist

ent

4.2x

�y

�3

5.4x

�y

��

26.

3x�

y�

2

x�

2y�

4co

nsi

sten

t 2x

��

�1

con

sist

ent

x�

y�

6 co

nsi

sten

t

and

ind

epen

den

t an

d d

epen

den

t an

d in

dep

end

ent

x

y

O

x

y

Ox

y

O

y � 2

x

y

Ox

y

Ox

y

O

1 � 3

x

y O

( –3,

–3)

Stud

y G

uide

and

Inte

rven

tion

(co

ntin

ued)

So

lvin

g S

yste

ms

of

Eq

uat

ion

s by

Gra

ph

ing

Exam

ple

Exer

cise

s

Answers (Lesson 3-1)

A1-A19 A2-03-873973 5/22/06 8:25 AM Page A2

Page 3: Answers (Lesson 3-1) · A system of equations is a set of two or more equations containing the same variables. You can solve a system of linear equations by graphing the equations

Chapter 3 A3 Glencoe Algebra 2

An

swer

s

Cha

pter

38

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Skill

s Pr

acti

ceS

olv

ing

Sys

tem

s o

f E

qu

atio

ns

By

Gra

ph

ing

Sol

ve e

ach

sys

tem

of

equ

atio

ns

by

grap

hin

g.

1.x

�2

2.y

��

3x�

63.

y�

4 �

3x

y�

0(2

,0)

y�

2x�

4(2

,0)

y�

�x

�1

(2,�

2)

4.y

�4

�x

5.y

��

2x�

26.

y�

x

y�

x�

2(3

,1)

y�

x�

5(3

,�4)

y�

�3x

�4

(1,1

)

7.x

�y

�3

8.x

�y

�4

9.3x

�2y

�4

x�

y�

1(2

,1)

2x�

5y�

8(4

,0)

2x�

y�

1(�

2,�

5)

Gra

ph

eac

h s

yste

m o

f eq

uat

ion

s an

d d

escr

ibe

it a

s co

nsi

sten

t a

nd

ind

epen

den

t,co

nsi

sten

t a

nd

dep

end

ent,

or i

nco

nsi

sten

t.

10.y

��

3x11

.y�

x�

512

.2x

�5y

�10

y�

�3x

�2

�2x

�2y

��

103x

�y

�15

inco

nsi

sten

tco

nsi

sten

t an

d

con

sist

ent

and

d

epen

den

tin

dep

end

ent

( 5, 0

)

2

2x

y

O

x

y

O

x

y

O

( –2,

–5)

x

y

O( 4

, 0)

x

y

O( 2

, 1)

x

y

O

( 1, 1

)

x

y

O( 3

, –4)

x

y

O

( 3, 1

)

x

y

O

1 � 3

( 2, –

2)x

y

O( 2

, 0)

x

y

O( 2

, 0)

x

y

O

1 � 2

3-1

Lesson 3-1

Cha

pter

39

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-1

Copyright ©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Sol

ve e

ach

sys

tem

of

equ

atio

ns

by

grap

hin

g.

1.x

�2y

�0

2.x

�2y

�4

3.2x

�y

�3

y�

2x�

3(2

,1)

2x�

3y�

1(2

,1)

y�

x�

(3,�

3)

4.y

�x

�3

5.2x

�y

�6

6.5x

�y

�4

y�

1(�

2,1)

x�

2y�

�2

(2,�

2)�

2x�

6y�

4(1

,1)

Gra

ph

eac

h s

yste

m o

f eq

uat

ion

s an

d d

escr

ibe

it a

s co

nsi

sten

t a

nd

ind

epen

den

t,co

nsi

sten

ta

nd

dep

end

ent,

or i

nco

nsi

sten

t.

7.2x

�y

�4

8.y

��

x�

29.

2y�

8 �

x

x�

y�

2x

�y

��

4y

�x

�4

con

sist

ent

and

ind

ep.

inco

nsi

sten

tco

nsi

sten

t an

d d

ep.

SOFT

WA

RE

For

Exe

rcis

es 1

0–12

,use

th

e fo

llow

ing

info

rmat

ion

.L

ocat

ion

Map

pin

g n

eeds

new

sof

twar

e.S

oftw

are

A c

osts

$13

,000

plu

s $5

00 p

er a

ddit

ion

alsi

te l

icen

se.S

oftw

are

B c

osts

$25

00 p

lus

$120

0 pe

r ad

diti

onal

sit

e li

cen

se.

10.W

rite

tw

o eq

uat

ion

s th

at r

epre

sen

t th

e co

st o

f ea

ch s

oftw

are.

A:

y�

13,0

00 �

500x

,B

:y

�25

00 �

1200

x

11.G

raph

th

e eq

uat

ion

s.E

stim

ate

the

brea

k-ev

en

poin

t of

th

e so

ftw

are

cost

s.15

ad

dit

ion

al li

cen

ses

12.I

f L

ocat

ion

Map

pin

g pl

ans

to b

uy

10 a

ddit

ion

al

site

lic

ense

s,w

hic

h s

oftw

are

wil

l co

st l

ess?

B

( 15,

20,

500)

A

B

So

ftw

are

Co

sts

Ad

dit

ion

al L

icen

ses

Total Cost ($)

40

812

1416

1820

26

10

24,0

00

20,0

00

16,0

00

12,0

00

8,00

0

4,00

0

x

y

O

x

y

O( 2

, 0)

x

y

O

1 � 2

y

xO

( 1, 1

)x

y O( 2

, –2)

x

y

O

( –2,

1)

( 3, –

3)

x

y

O( 2

, 1) x

y

O

( 2, 1

)

x

y

O

9 � 21 � 2

Prac

tice

So

lvin

g S

yste

ms

of

Eq

uat

ion

s B

y G

rap

hin

g

Answers (Lesson 3-1)

A1-A19 A2-03-873973 5/22/06 8:25 AM Page A3

Page 4: Answers (Lesson 3-1) · A system of equations is a set of two or more equations containing the same variables. You can solve a system of linear equations by graphing the equations

Chapter 3 A4 Glencoe Algebra 2

Cha

pter

310

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Wor

d Pr

oble

m P

ract

ice

So

lvin

g S

yste

ms

of

Eq

uat

ion

s B

y G

rap

hin

g1.

STR

EETS

An

drew

is

stu

dyin

g a

map

an

dn

otic

es t

wo

stre

ets

that

ru

n p

aral

lel

toea

ch o

ther

.He

com

pute

s th

e eq

uat

ion

sof

th

e li

nes

th

at r

epre

sen

t th

e tw

o ro

ads.

Are

th

ese

two

equ

atio

ns

con

sist

ent

orin

con

sist

ent?

If

they

are

con

sist

ent,

are

they

in

dep

end

ent

or d

epen

den

t? E

xpla

in.

Th

ey a

re in

con

sist

ent.

Par

alle

llin

es n

ever

inte

rsec

t so

th

ere

isn

o s

olu

tio

n.

2.SP

OTL

IGH

TSS

hip

A h

as c

oord

inat

es(�

1,�

2) a

nd

Sh

ip B

has

coo

rdin

ates

(�

4,1)

.Bot

h s

hip

s h

ave

thei

r sp

otli

ghts

fixa

ted

on t

he

sam

e li

febo

at.T

he

ligh

tbe

am f

rom

Sh

ip A

tra

vels

alo

ng

the

lin

ey

�2x

.Th

e li

ght

beam

fro

m S

hip

Btr

avel

s al

ong

the

lin

e y

�x

�5.

Wh

atar

e th

e co

ordi

nat

es o

f th

e li

febo

at?

(5,1

0)

3.LA

SER

SA

mac

hin

e h

eats

up

a si

ngl

epo

int

by s

hin

ing

seve

ral

lase

rs a

t it

.Th

eeq

uat

ion

s y

�x

�1

and

y�

�x

�7

desc

ribe

tw

o of

th

e la

ser

beam

s.G

raph

both

of

thes

e li

nes

to

fin

d th

eco

ordi

nat

es o

f th

e h

eate

d po

int

(3,4

)

4.PA

THS

Th

e gr

aph

sh

ows

the

path

s of

two

peop

le w

ho

took

a w

alk

in a

par

k.W

her

e di

d th

eir

path

s in

ters

ect?

(6,6

)

PHO

NE

SER

VIC

EF

or E

xerc

ises

5–7

,use

the

foll

owin

g in

form

atio

n.

Bet

h i

s de

cidi

ng

betw

een

tw

o te

leph

one

plan

s.P

lan

A c

har

ges

$15

per

mon

th p

lus

10 c

ents

per

min

ute

.Pla

n B

ch

arge

s $2

0 pe

rm

onth

plu

s 5

cen

ts p

er m

inu

te.

5.W

rite

a s

yste

m o

f eq

uat

ion

s th

atre

pres

ent

the

mon

thly

cos

t of

eac

h p

lan

.y

�0.

1x+

15y

�0.

05x

+ 20

6.G

raph

th

e eq

uat

ion

s.

7.F

or h

ow m

any

min

ute

s pe

r m

onth

do

the

two

phon

e pl

ans

cost

th

e sa

me

amou

nt?

100

min

ute

s

y

xO5

10

y

xO

5

5

y

xO5

5

y

xO

5

5�

5

Ship

B

Ship

A

Exer

cise

s

Exam

ple

s

3-1

Lesson 3-1

Cha

pter

311

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-1

Copyright ©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Enri

chm

ent

So

luti

on

s to

No

nlin

ear

Eq

uat

ion

s R

eal-

life

sit

uat

ion

s ar

e of

ten

not

cap

able

of

bein

g re

pres

ente

d by

a l

inea

r eq

uat

ion

.S

yste

ms

of n

onli

nea

r eq

uat

ion

s ar

e of

ten

use

d in

th

e st

udy

of

popu

lati

on d

ynam

ics,

mod

elin

g ca

rbon

mon

oxid

e ex

posu

re,a

nd

dete

rmin

ing

the

hei

ght

of a

n o

bjec

t in

fre

e fa

ll.

Non

lin

ear

equ

atio

ns

hav

e on

e va

riab

le r

aise

d to

a p

ower

oth

er t

han

on

e or

mu

ltip

lica

tion

of t

wo

or m

ore

vari

able

s.

a.xy

�1

or y

��1 x�

The

firs

t eq

uatio

n ha

s a

prod

uct

of t

wo

varia

bles

.

The

sec

ond

is t

he s

ame

equa

tion

solv

ed fo

r y.

b.y

�x3

� 2

x�

1T

he v

aria

ble

xis

rai

sed

to t

he t

hird

pow

er.

Sys

tem

s of

non

lin

ear

equ

atio

ns

con

sist

of

two

or m

ore

equ

atio

ns,

wh

ere

at l

east

on

e is

non

lin

ear.

Sol

uti

ons

to t

hes

e sy

stem

s ar

e ty

pica

lly

diff

icu

lt t

o fi

nd.

On

e u

sefu

l m

eth

od f

or f

indi

ng

solu

tion

s to

sys

tem

s of

non

lin

ear

equ

atio

ns

is t

he

sam

e as

th

e m

eth

od f

or f

indi

ng

solu

tion

s to

syst

ems

of l

inea

r eq

uat

ion

s—u

se t

ech

nol

ogy

to g

raph

th

esy

stem

an

d fi

nd

the

poin

t(s)

of

inte

rsec

tion

.Th

e gr

aph

of

the

syst

em i

s sh

own

at

the

righ

t.

y�

�1 x�

y �

x3�

2x

� 1

Usi

ng

the

Inte

rsec

tion

fu

nct

ion

of

a gr

aph

ing

calc

ula

tor

you

fin

d th

at o

ne

poin

t of

inte

rsec

tion

is

appr

oxim

atel

y (1

.345

09,0

.743

445)

.

1.U

se a

gra

phin

g ca

lcu

lato

r to

fin

d th

e ot

her

poi

nt

of i

nte

rsec

tion

.(�

1.71

064,

�0.

5845

75)

2.U

se t

he

Zoo

mfe

atu

re o

n t

he

calc

ula

tor

to z

oom

in

aro

un

d th

e po

int

of i

nte

rsec

tion

.W

hat

do

the

two

non

lin

ear

equ

atio

ns

rem

ind

you

of

at t

his

lev

el o

f zo

om?

Th

ey s

ho

uld

ap

pea

r to

be

linea

r.

3.G

OLF

Th

e h

eigh

t of

a g

olf

ball

dro

pped

fro

m t

he

top

of a

100

-foo

t to

wer

aft

er

tse

con

ds i

s gi

ven

by

h�

�16

t3�

100.

Use

a g

raph

ing

calc

ula

tor

to d

eter

min

e w

hen

(in

sec

onds

) th

e go

lf b

all

is 1

0 fe

et f

rom

th

e gr

oun

d.2.

3717

1 se

con

ds

⎧ ⎨ ⎩

Answers (Lesson 3-1)

A1-A19 A2-03-873973 5/22/06 8:25 AM Page A4

Page 5: Answers (Lesson 3-1) · A system of equations is a set of two or more equations containing the same variables. You can solve a system of linear equations by graphing the equations

Chapter 3 A5 Glencoe Algebra 2

An

swer

s

Exer

cise

s

Cha

pter

312

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Spre

adsh

eet

Act

ivit

yB

reak

-Eve

n P

oin

t

1.If

Car

ly c

ould

dec

reas

e h

er a

nn

ual

ove

rhea

d to

$14

,000

,wh

at w

ould

th

ebr

eak-

even

poi

nt

be?

bet

wee

n 1

400

and

150

0 ca

nd

les

2.S

upp

ose

Car

ly d

ecre

ases

her

an

nu

al o

verh

ead

to $

14,0

00 a

nd

incr

ease

sth

e pr

ice

of a

can

dle

to $

14.0

0.W

hat

is

the

new

bre

ak-e

ven

poi

nt?

bet

wee

n 1

200

and

130

0 ca

nd

les

Car

ly E

rics

on i

s co

nsi

der

ing

open

ing

a ca

nd

le

bu

sin

ess.

Sh

e es

tim

ates

th

at s

he

wil

l h

ave

an a

nn

ual

ove

rhea

d o

f$1

5,00

0.It

cos

ts C

arly

$3.

00 t

o m

ake

a ja

r ca

nd

le,w

hic

h s

he

sell

s fo

r$1

2.50

.Wh

at i

s C

arly

’s b

reak

-eve

n p

oin

t?

Use

Col

um

n A

for

th

e n

um

ber

of c

andl

es.C

olu

mn

s B

and

C a

re t

he

cost

an

d th

e in

com

e,re

spec

tive

ly.

Ext

end

the

row

s of

th

e sp

read

shee

t to

fin

d th

e po

int

atw

hich

the

inco

me

firs

t ex

ceed

s th

e co

st.T

he b

reak

-eve

npo

int

occu

rs b

etw

een

th

is p

oin

t an

d th

e pr

evio

us

poin

t.In

th

is c

ase,

the

brea

k ev

en p

oin

t oc

curs

bet

wee

n 1

500

and

1600

can

dles

.

Th

e ch

art

tool

of

the

spre

adsh

eet

allo

ws

you

to

grap

hth

e da

ta.T

he

grap

h v

erif

ies

the

solu

tion

.

You

hav

e le

arn

ed t

hat

th

e br

eak-

even

poi

nt

is t

he

poin

t at

wh

ich

th

e in

com

eeq

ual

s th

e co

st.Y

ou c

an u

se t

he

form

ula

s an

d ch

arts

in

a s

prea

dsh

eet

to f

ind

a br

eak-

even

poi

nt.

A1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

C

$0$1

,250

$2,5

00$3

,750

$5,0

00$6

,250

$7,5

00$8

,750

$10,

000

$11,

250

$12,

500

$13,

750

$15,

000

$16,

250

$17,

500

$18,

750

$20,

000

Inco

me

B

$15,

000

$15,

300

$15,

600

$15,

900

$16,

200

$16,

500

$16,

800

$17,

100

$17,

400

$17,

700

$18,

000

$18,

300

$18,

600

$18,

900

$19,

200

$19,

500

$19,

800

Cos

tC

andl

es0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

1500

1600

Sh

eet

1S

hee

t 2

Sh

eet

3

Exam

ple

Lesson 3-1

Cha

pter

313

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-2

Copyright ©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Less

on R

eadi

ng G

uide

So

lvin

g S

yste

ms

of

Eq

uat

ion

s A

lgeb

raic

ally

Get

Rea

dy

for

the

Less

on

Rea

d t

he

intr

odu

ctio

n t

o L

esso

n 3

-2 i

n y

our

text

boo

k.

•H

ow m

any

mor

e m

inu

tes

of l

ong

dist

ance

tim

e di

d Yo

lan

da u

se i

n F

ebru

ary

than

in

Jan

uar

y?13

min

ute

s

•H

ow m

uch

mor

e w

ere

the

Feb

ruar

y ch

arge

s th

an t

he

Jan

uar

y ch

arge

s?$1

.04

•U

sin

g yo

ur

answ

ers

for

the

ques

tion

s ab

ove,

how

can

you

fin

d th

e ra

te p

er m

inu

te?

Fin

d $

1.04

�13

.

Rea

d t

he

Less

on

1.S

upp

ose

that

you

are

ask

ed t

o so

lve

the

syst

em o

f eq

uat

ion

s 4x

�5y

�7

at t

he

righ

t by

th

e su

bsti

tuti

on m

eth

od.

3x�

y�

�9

Th

e fi

rst

step

is

to s

olve

on

e of

th

e eq

uat

ion

s fo

r on

e va

riab

le

in t

erm

s of

th

e ot

her

.To

mak

e yo

ur

wor

k as

eas

y as

pos

sibl

e,w

hic

h e

quat

ion

wou

ld y

ou s

olve

for

wh

ich

var

iabl

e? E

xpla

in.

Sam

ple

an

swer

:S

olv

e th

e se

con

d e

qu

atio

n f

or

yb

ecau

se in

th

ateq

uat

ion

th

e va

riab

le y

has

a c

oef

fici

ent

of

1.

2.S

upp

ose

that

you

are

ask

ed t

o so

lve

the

syst

em o

f eq

uat

ion

s 2x

�3y

��

2at

th

e ri

ght

by t

he

elim

inat

ion

met

hod

.7x

�y

�39

To

mak

e yo

ur

wor

k as

eas

y as

pos

sibl

e,w

hic

h v

aria

ble

wou

ld

you

eli

min

ate?

Des

crib

e h

ow y

ou w

ould

do

this

.S

amp

le a

nsw

er:

Elim

inat

e th

e va

riab

le y

;m

ult

iply

th

e se

con

d e

qu

atio

n b

y3

and

th

en a

dd

th

e re

sult

to

th

e fi

rst

equ

atio

n.

Rem

emb

er W

hat

Yo

u L

earn

ed

3.T

he

subs

titu

tion

met

hod

an

d el

imin

atio

n m

eth

od f

or s

olvi

ng

syst

ems

both

hav

e se

vera

lst

eps,

and

it m

ay b

e di

ffic

ult

to

rem

embe

r th

em.Y

ou m

ay b

e ab

le t

o re

mem

ber

them

mor

e ea

sily

if

you

not

ice

wh

at t

he

met

hod

s h

ave

in c

omm

on.W

hat

ste

p is

th

e sa

me

inbo

th m

eth

ods?

Sam

ple

an

swer

:A

fter

fin

din

g t

he

valu

e o

f o

ne

of

the

vari

able

s,yo

u f

ind

the

valu

e o

f th

e o

ther

var

iab

le b

y su

bst

itu

tin

g t

he

valu

e yo

u h

ave

fou

nd

in o

ne

of

the

ori

gin

al e

qu

atio

ns.

Answers (Lessons 3-1 and 3-2)

A1-A19 A2-03-873973 5/22/06 8:25 AM Page A5

Page 6: Answers (Lesson 3-1) · A system of equations is a set of two or more equations containing the same variables. You can solve a system of linear equations by graphing the equations

Chapter 3 A6 Glencoe Algebra 2

Cha

pter

314

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-2

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Sub

stit

uti

on

To

solv

e a

syst

em o

f li

nea

r eq

uat

ion

s by

su

bst

itu

tion

,fir

st s

olve

for

on

eva

riab

le i

n t

erm

s of

th

e ot

her

in

on

e of

th

e eq

uat

ion

s.T

hen

su

bsti

tute

th

is e

xpre

ssio

n i

nto

the

oth

er e

quat

ion

an

d si

mpl

ify.

Use

su

bst

itu

tion

to

solv

e th

e sy

stem

of

equ

atio

ns.

2x�

y�

9x

�3y

��

6S

olve

th

e fi

rst

equ

atio

n f

or y

in t

erm

s of

x.

2x�

y�

9F

irst

equa

tion

�y

��

2x�

9S

ubtr

act

2xfr

om b

oth

side

s.

y�

2x�

9M

ultip

ly b

oth

side

s by

�1.

Su

bsti

tute

th

e ex

pres

sion

2x

�9

for

yin

to t

he

seco

nd

equ

atio

n a

nd

solv

e fo

r x.

x�

3y�

�6

Sec

ond

equa

tion

x�

3(2x

�9)

��

6S

ubst

itute

2x

�9

for

y.

x�

6x�

27 �

�6

Dis

trib

utiv

e P

rope

rty

7x�

27 �

�6

Sim

plify

.

7x�

21A

dd 2

7 to

eac

h si

de.

x�

3D

ivid

e ea

ch s

ide

by 7

.

Now

,su

bsti

tute

th

e va

lue

3 fo

r x

in e

ith

er o

rigi

nal

equ

atio

n a

nd

solv

e fo

r y.

2x�

y�

9F

irst

equa

tion

2(3)

�y

�9

Rep

lace

xw

ith 3

.

6 �

y�

9S

impl

ify.

�y

�3

Sub

trac

t 6

from

eac

h si

de.

y�

�3

Mul

tiply

eac

h si

de b

y �

1.

Th

e so

luti

on o

f th

e sy

stem

is

(3,�

3).

Sol

ve e

ach

sys

tem

of

lin

ear

equ

atio

ns

by

usi

ng

sub

stit

uti

on.

1.3x

�y

�7

2.2x

�y

�5

3.2x

�3y

��

34x

�2y

�16

3x�

3y�

3x

�2y

�2

(�1,

10)

(2,1

)(�

12,7

)

4.2x

�y

�7

5.4x

�3y

�4

6.5x

�y

�6

6x�

3y�

142x

�y

��

83

�x

�0

no

so

luti

on

(�2,

�4)

(3,�

9)

7.x

�8y

��

28.

2x�

y�

�4

9.x

�y

��

2x

�3y

�20

4x�

y�

12x

�3y

�2

(14,

�2)

��,3

�(�

8,�

6)

10.x

�4y

�4

11.x

�3y

�2

12.2

x�

2y�

42x

�12

y�

134x

�12

y�

8x

�2y

�0

�5,�

infi

nit

ely

man

y�

,�

2 � 34 � 3

1 � 4

1 � 2

Stud

y G

uide

and

Inte

rven

tion

So

lvin

g S

yste

ms

of

Eq

uat

ion

s A

lgeb

raic

ally

Exam

ple

Exer

cise

s

3-2

Lesson 3-2

Cha

pter

315

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-2

Copyright ©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Elim

inat

ion

To

solv

e a

syst

em o

f li

nea

r eq

uat

ion

s by

eli

min

atio

n,a

dd o

r su

btra

ct t

he

equ

atio

ns

to e

lim

inat

e on

e of

th

e va

riab

les.

You

may

fir

st n

eed

to m

ult

iply

on

e or

bot

h o

f th

eeq

uat

ion

s by

a c

onst

ant

so t

hat

on

e of

th

e va

riab

les

has

th

e sa

me

(or

oppo

site

) co

effi

cien

t in

one

equ

atio

n a

s it

has

in

th

e ot

her

.

Use

th

e el

imin

atio

n m

eth

od t

o so

lve

the

syst

em o

f eq

uat

ion

s.2x

�4y

��

263x

�y

��

24

Stud

y G

uide

and

Inte

rven

tion

(co

ntin

ued)

So

lvin

g S

yste

ms

of

Eq

uat

ion

s A

lgeb

raic

ally

Mu

ltip

ly t

he

seco

nd

equ

atio

n b

y 4.

Th

en s

ubt

ract

the

equ

atio

ns

to e

lim

inat

e th

e y

vari

able

.2x

�4y

��

262x

�4y

��

263x

�y

��

24M

ultip

ly b

y 4.

12x

�4y

��

96�

10x

�70

x�

�7

Rep

lace

xw

ith

�7

and

solv

e fo

r y.

2x�

4y�

�26

2(�

7) �

4y�

�26

�14

�4y

��

26�

4y�

�12

y�

3T

he

solu

tion

is

(�7,

3).

Mu

ltip

ly t

he

firs

t eq

uat

ion

by

3 an

d th

e se

con

deq

uat

ion

by

2.T

hen

add

th

e eq

uat

ion

s to

elim

inat

e th

e y

vari

able

.3x

�2y

�4

Mul

tiply

by

3.9x

�6y

�12

5x�

3y�

�25

Mul

tiply

by

2.10

x�

6y�

�50

19x

��

38x

��

2

Rep

lace

xw

ith

�2

and

solv

e fo

r y.

3x�

2y�

43(

�2)

�2y

�4

�6

�2y

�4

�2y

�10

y�

�5

Th

e so

luti

on i

s (�

2,�

5).

Use

th

e el

imin

atio

n m

eth

od t

o so

lve

the

syst

em o

f eq

uat

ion

s.3x

�2y

�4

5x�

3y�

�25

Sol

ve e

ach

sys

tem

of

equ

atio

ns

by

usi

ng

elim

inat

ion

.

1.2x

�y

�7

2.x

�2y

�4

3.3x

�4y

��

104.

3x�

y�

123x

�y

�8

�x

�6y

�12

x�

4y�

25x

�2y

�20

(3,�

1)(1

2,4)

(�2,

�1)

(4,0

)

5.4x

�y

�6

6.5x

�2y

�12

7.2x

�y

�8

8.7x

�2y

��

1

2x�

�4

�6x

�2y

��

143x

�y

�12

4x�

3y�

�13

no

so

luti

on

(2,1

)in

fin

itel

y m

any

(�1,

3)

9.3x

�8y

��

610

.5x

�4y

�12

11.�

4x�

y�

�12

12.5

m�

2n�

�8

x�

y�

97x

�6y

�40

4x�

2y�

64m

�3n

�2

(6,�

3)(4

,�2)

�,�

2 �(�

4,6)

5 � 2

3 � 2y � 2

Exam

ple

1

Exam

ple

2

Exer

cise

s

Answers (Lesson 3-2)

A1-A19 A2-03-873973 5/22/06 8:25 AM Page A6

Page 7: Answers (Lesson 3-1) · A system of equations is a set of two or more equations containing the same variables. You can solve a system of linear equations by graphing the equations

Chapter 3 A7 Glencoe Algebra 2

An

swer

s

Cha

pter

316

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-2

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Skill

s Pr

acti

ceS

olv

ing

Sys

tem

s o

f E

qu

atio

ns

Alg

ebra

ical

lyS

olve

eac

h s

yste

m o

f eq

uat

ion

s b

y u

sin

g su

bst

itu

tion

.

1.m

�n

�20

2.x

�3y

��

33.

w�

z�

1m

�n

��

4(8

,12)

4x�

3y�

6(3

,�2)

2w�

3z�

12(3

,2)

4.3r

�s

�5

5.2b

�3c

��

46.

x�

y�

�5

2r�

s�

5(2

,�1)

b�

c�

3(1

3,�

10)

3x�

4y�

13(�

1,4)

Sol

ve e

ach

sys

tem

of

equ

atio

ns

by

usi

ng

elim

inat

ion

.

7.2p

�q

�17

8.2j

�k

�3

9.3c

�2d

�2

3p�

q�

8(5

,�7)

3j�

k�

2(1

,�1)

3c�

4d�

50(6

,8)

10.2

f�

3g�

911

.�2x

�y

��

112

.2x

�y

�12

f�

g�

2(3

,1)

x�

2y�

3(1

,1)

2x�

y�

6n

o s

olu

tio

n

Sol

ve e

ach

sys

tem

of

equ

atio

ns

by

usi

ng

eith

er s

ub

stit

uti

on o

r el

imin

atio

n.

13.�

r�

t�

514

.2x

�y

��

515

.x�

3y�

�12

�2r

�t

�4

(1,6

)4x

�y

�2

��,4

�2x

�y

�11

(3,5

)

16.2

p�

3q�

617

.6w

�8z

�16

18.

c�

d�

6�

2p�

3q�

�6

3w�

4z�

8c

�d

�0

(3,3

)in

fin

itel

y m

any

infi

nit

ely

man

y

19.2

u�

4v�

�6

20.3

a�

b�

�1

21.2

x�

y�

6u

�2v

�3

no

so

luti

on

�3a

�b

�5

(�1,

2)3x

�2y

�16

(4,�

2)

22.3

y�

z�

�6

23.c

�2d

��

224

.3r

�2s

�1

�3y

�z

�6

(�2,

0)�

2c�

5d�

3(�

4,1)

2r�

3s�

9(�

3,�

5)

25.T

he

sum

of

two

nu

mbe

rs i

s 12

.Th

e di

ffer

ence

of

the

sam

e tw

o n

um

bers

is

�4.

Fin

d th

e n

um

bers

.4,

8

26.T

wic

e a

nu

mbe

r m

inu

s a

seco

nd

nu

mbe

r is

�1.

Tw

ice

the

seco

nd

nu

mbe

r ad

ded

to t

hre

e ti

mes

th

e fi

rst

nu

mbe

r is

9.F

ind

the

two

nu

mbe

rs.

1,3

1 � 2

3-2

Lesson 3-2

Cha

pter

317

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-2

Copyright ©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Sol

ve e

ach

sys

tem

of

equ

atio

ns

by

usi

ng

sub

stit

uti

on.

1.2x

�y

�4

2.x

�3y

�9

3.g

�3h

�8

no

3x�

2y�

1(7

,�10

)x

�2y

��

1(3

,�2)

g�

h�

9so

luti

on

4.2a

�4b

�6

infi

nit

ely

5.2m

�n

�6

6.4x

�3y

��

6�

a�

2b�

�3

man

y5m

�6n

�1

(5,�

4)�

x�

2y�

7(�

3,�

2)

7.u

�2v

�8.

x�

3y�

169.

w�

3z�

1

�u

�2v

�5

no

so

luti

on

4x�

y�

9(1

,�5)

3w�

5z�

�4

��,

Sol

ve e

ach

sys

tem

of

equ

atio

ns

by

usi

ng

elim

inat

ion

.

10.2

r�

s�

511

.2m

�n

��

112

.6x

�3y

�6

3r�

s�

20(5

,�5)

3m�

2n�

30(4

,9)

8x�

5y�

12(�

1,4)

13.3

j�

k�

1014

.2x

�y

��

4n

o

15.2

g�

h�

64j

�k

�16

(6,8

)�

4x�

2y�

6so

luti

on

3g�

2h�

16(4

,�2)

16.2

t�

4v�

6in

fin

itel

y17

.3x

�2y

�12

18.

x�

3y�

11�

t�

2v�

�3

man

y2x

�y

�14

(6,3

)8x

�5y

�17

(4,3

)

Sol

ve e

ach

sys

tem

of

equ

atio

ns

by

usi

ng

eith

er s

ub

stit

uti

on o

r el

imin

atio

n.

19.8

x�

3y�

�5

20.8

q�

15r

��

4021

.3x

�4y

�12

infi

nit

ely

10x

�6y

��

13�

,�3 �

4q�

2r�

56(1

0,8)

x�

y�

man

y

22.4

b�

2d�

5n

o23

.s�

3y�

424

.4m

�2p

�0

�2b

�d

�1

solu

tio

ns

�1

(1,1

)�

3m�

9p�

5�

,�

25.5

g�

4k�

1026

.0.5

x�

2y�

527

.h�

z�

3n

o�

3g�

5k�

7(6

,�5)

x�

2y�

�8

(�2,

3)�

3h�

3z�

6so

luti

on

SPO

RTS

For

Exe

rcis

es 2

8 an

d 2

9,u

se t

he

foll

owin

g in

form

atio

n.

Las

t ye

ar t

he

voll

eyba

ll t

eam

pai

d $5

per

pai

r fo

r so

cks

and

$17

per

pair

for

sh

orts

on

ato

tal

purc

has

e of

$31

5.T

his

yea

r th

ey s

pen

t $3

42 t

o bu

y th

e sa

me

nu

mbe

r of

pai

rs o

f so

cks

and

shor

ts b

ecau

se t

he

sock

s n

ow c

ost

$6 a

pai

r an

d th

e sh

orts

cos

t $1

8.

28.W

rite

a s

yste

m o

f tw

o eq

uat

ion

s th

at r

epre

sen

ts t

he

nu

mbe

r of

pai

rs o

f so

cks

and

shor

tsbo

ugh

t ea

ch y

ear.

5x�

17y

�31

5,6x

�18

y�

342

29.H

ow m

any

pair

s of

soc

ks a

nd

shor

ts d

id t

he

team

bu

y ea

ch y

ear?

sock

s:12

,sh

ort

s:15

2 � 31 � 3

4 � 34 � 9

1 � 31 � 2

2 � 3

1 � 2

1 � 21 � 2

1 � 2

1 � 3

Prac

tice

S

olv

ing

Sys

tem

s o

f E

qu

atio

ns

Alg

ebra

ical

ly

Answers (Lesson 3-2)

A1-A19 A2-03-873973 5/22/06 8:25 AM Page A7

Page 8: Answers (Lesson 3-1) · A system of equations is a set of two or more equations containing the same variables. You can solve a system of linear equations by graphing the equations

Chapter 3 A8 Glencoe Algebra 2

Cha

pter

318

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-2

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Wor

d Pr

oble

m P

ract

ice

So

lvin

g S

yste

ms

of

Eq

uat

ion

s A

lgeb

raic

ally

1.SU

PPLI

ESK

irst

a an

d A

rth

ur

both

nee

dpe

ns

and

blan

k C

Ds.

Th

e eq

uat

ion

th

atre

pres

ents

Kir

sta’

s pu

rch

ases

is

y�

27 �

3x.T

he

equ

atio

n t

hat

repr

esen

ts A

rth

ur’

s pu

rch

ases

is

y�

17 �

x.If

xre

pres

ents

th

e pr

ice

of t

he

pen

s,an

d y

repr

esen

ts t

he

pric

e of

the

CD

s,w

hat

are

th

e pr

ices

of

the

pen

san

d th

e C

Ds?

pen

s ar

e $5

a p

ack,

CD

s ar

e $1

2 a

pac

k

2.W

ALK

ING

Am

y is

wal

kin

g a

stra

igh

tpa

th t

hat

can

be

repr

esen

ted

by t

he

equ

atio

n y

�2x

�3.

At

the

sam

e ti

me

Ken

dra

is w

alki

ng

the

stra

igh

t pa

thth

at h

as t

he

equ

atio

n 3

y�

6x�

6.W

hat

is

the

solu

tion

to

the

syst

em o

feq

uat

ion

s th

at r

epre

sen

ts t

he

path

s th

e tw

o gi

rls

wal

ked?

Exp

lain

.T

her

e is

no

so

luti

on

.Th

eir

pat

hs

nev

er c

ross

.

3.C

AFE

TER

IAT

o fu

rnis

h a

caf

eter

ia,a

sch

ool

can

spe

nd

$520

0 on

tab

les

and

chai

rs.T

able

s co

st $

200

and

chai

rs c

ost

$40.

Eac

h t

able

wil

l h

ave

8 ch

airs

arou

nd

it.H

ow m

any

tabl

es a

nd

chai

rsw

ill

the

sch

ool

purc

has

e?10

tab

les

and

80

chai

rs

4.PR

ICES

At

a st

ore,

toot

hbr

ush

es c

ost

xdo

llar

s an

d ba

rs o

f so

ap c

ost

ydo

llar

s.O

ne

cust

omer

bou

ght

2 to

oth

bru

shes

and

1 ba

r of

soa

p fo

r $1

1.A

not

her

cust

omer

bou

ght

6 to

oth

bru

shes

an

d 5

bars

of

soap

for

$38

.Bot

h a

mou

nts

do

not

in

clu

de t

ax.W

rite

an

d so

lve

asy

stem

of

equ

atio

ns

for

xan

d y.

2x+

y�

116x

+ 5y

�38

x�

4.25

an

d y

�2.

50

GA

MES

For

Exe

rcis

es 5

–7,u

se t

he

foll

owin

g in

form

atio

n.

Mar

k an

d S

teph

anie

are

pla

yin

g a

gam

ew

her

e th

ey t

oss

a da

rt a

t a

gam

e bo

ard

that

is h

angi

ng

on t

he

wal

l.T

he

poin

ts e

arn

edfr

om a

tos

s de

pen

ds o

n w

her

e th

e da

rtla

nds

.Th

e ce

nte

r ar

ea i

s w

orth

mor

e po

ints

than

th

e su

rrou

ndi

ng

area

.Eac

h p

laye

rto

sses

12

dart

s.

5.S

teph

anie

ear

ned

a t

otal

of

66 p

oin

tsw

ith

6 d

arts

lan

din

g in

eac

h a

rea.

Mar

kea

rned

a t

otal

of

56 p

oin

ts w

ith

4 d

arts

lan

din

g in

th

e ce

nte

r ar

ea,a

nd

8 da

rts

lan

din

g in

th

e su

rrou

ndi

ng

area

.Wri

te a

syst

em o

f eq

uat

ion

s th

at r

epre

sen

ts t

he

nu

mbe

r of

dar

ts e

ach

pla

yer

toss

ed i

nto

each

sec

tion

.Use

xfo

r th

e in

ner

cir

cle,

and

yfo

r th

e ou

ter

circ

le.

6x+

6y�

66;

4x+

8y�

56

6.H

ow m

any

poin

ts i

s th

e in

ner

cir

cle

wor

th?

How

man

y po

ints

is

the

oute

rci

rcle

wor

th?

inn

er c

ircl

e �

8 p

oin

ts;

ou

ter

circ

le �

3 p

oin

ts

7.If

a p

laye

r ge

ts 1

0 da

rts

in t

he

inn

erci

rcle

an

d 2

in t

he

oute

r ci

rcle

th

e to

tal

scor

e is

dou

bled

.How

man

y po

ints

wou

ld t

he

play

er e

arn

if

he

or s

he

gets

exac

tly

10 d

arts

in

th

e ce

nte

r?17

2 p

oin

ts

3-2

Lesson 3-2

Cha

pter

319

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-2

Copyright ©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Enri

chm

ent

Usi

ng

Co

ord

inat

esF

rom

on

e ob

serv

atio

n p

oin

t,th

e li

ne

of s

igh

t to

a d

own

ed p

lan

e is

giv

en b

y y

�x

�1.

Th

is e

quat

ion

des

crib

es t

he

dist

ance

fro

m t

he

obse

rvat

ion

poi

nt

to t

he

plan

e in

a s

trai

ght

lin

e.F

rom

an

oth

er o

bser

vati

on p

oin

t,th

e li

ne

of

sigh

t is

giv

en b

y x

�3y

�21

.Wh

at a

re t

he

coor

din

ates

of

the

poin

t at

wh

ich

th

e cr

ash

occ

urr

ed?

Sol

ve t

he

syst

em o

f eq

uat

ion

s�y

�x

�1

.x

�3y

�21

x�

3y�

21x

�3(

x�

1) �

21S

ubst

itute

x�

1 fo

r y.

x�

3x�

3 �

214x

�24

x�

6

x�

3y�

216

�3y

�21

Sub

stitu

te 6

for

x.

3y�

15y

�5

Th

e co

ordi

nat

es o

f th

e cr

ash

are

(6,

5).

Sol

ve.

1.T

he

lin

es o

f si

ght

to a

for

est

fire

are

as

foll

ows.

Fro

m R

ange

r S

tati

on A

:3x

�y

�9

Fro

m R

ange

r S

tati

on B

:2x

�3y

�13

Fin

d th

e co

ordi

nat

es o

f th

e fi

re.

(2,3

)

2.A

n a

irpl

ane

is t

rave

lin

g al

ong

the

lin

e x

�y

��

1 w

hen

it

sees

an

oth

er

airp

lan

e tr

avel

ing

alon

g th

e li

ne

5x�

3y�

19.I

f th

ey c

onti

nu

e al

ong

the

sam

e li

nes

,at

wh

at p

oin

t w

ill

thei

r fl

igh

t pa

ths

cros

s?(2

,3)

3.T

wo

min

e sh

afts

are

du

g al

ong

the

path

s of

th

e fo

llow

ing

equ

atio

ns.

x�

y�

1400

2x�

y�

1300

If t

he

shaf

ts m

eet

at a

dep

th o

f 20

0 fe

et,w

hat

are

th

e co

ordi

nat

es o

f th

e po

int

at w

hic

h t

hey

mee

t?(9

00,�

500)

Answers (Lesson 3-2)

A1-A19 A2-03-873973 5/22/06 8:25 AM Page A8

Page 9: Answers (Lesson 3-1) · A system of equations is a set of two or more equations containing the same variables. You can solve a system of linear equations by graphing the equations

Chapter 3 A9 Glencoe Algebra 2

An

swer

s

Cha

pter

320

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-3

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Less

onRe

adin

g G

uide

So

lvin

g S

yste

ms

of

Ineq

ual

itie

s by

Gra

ph

ing

Get

Rea

dy

for

the

Less

on

Rea

d t

he

intr

odu

ctio

n t

o L

esso

n 3

-3 i

n y

our

text

boo

k.

Sat

ish

is

37 y

ears

old

.He

has

a b

lood

pre

ssu

re r

eadi

ng

of 1

35/9

9.Is

his

blo

od p

ress

ure

wit

hin

th

e n

orm

al r

ange

? E

xpla

in.

Sam

ple

an

swer

:N

o;

his

sys

tolic

pre

ssu

re is

no

rmal

,bu

t h

is d

iast

olic

pre

ssu

re is

to

o h

igh

.It

sho

uld

be

bet

wee

n 6

0 an

d 9

0.

Rea

d t

he

Less

on

1.W

ith

out

actu

ally

dra

win

g th

e gr

aph

,des

crib

e th

e bo

un

dary

lin

es

⏐x⏐

�3

for

the

syst

em o

f in

equ

alit

ies

show

n a

t th

e ri

ght.

⏐y⏐

�5

Two

das

hed

ver

tica

l lin

es (

x�

3 an

d x

��

3) a

nd

tw

o s

olid

ho

rizo

nta

llin

es (

y�

�5

and

y�

5)

2.T

hin

k ab

out

how

th

e gr

aph

wou

ld l

ook

for

the

syst

em g

iven

abo

ve.W

hat

wil

l be

th

esh

ape

of t

he

shad

ed r

egio

n?

(It

is n

ot n

eces

sary

to

draw

th

e gr

aph

.See

if

you

can

imag

ine

it w

ith

out

draw

ing

anyt

hin

g.If

th

is i

s di

ffic

ult

to

do,m

ake

a ro

ugh

ske

tch

to

hel

p yo

u a

nsw

er t

he

ques

tion

.)a

rect

ang

le

3.W

hic

h s

yste

m o

f in

equ

alit

ies

mat

ches

th

e gr

aph

sh

own

at

th

e ri

ght?

BA

.x

�y

��

2B

.x

�y

��

2x

�y

�2

x�

y�

2

C.

x�

y�

�2

D.

x�

y�

�2

x�

y�

2x

�y

�2

Rem

emb

er W

hat

Yo

u L

earn

ed

4.T

o gr

aph

a s

yste

m o

f in

equ

alit

ies,

you

mu

st g

raph

tw

o or

mor

e bo

un

dary

lin

es.W

hen

you

gra

ph e

ach

of

thes

e li

nes

,how

can

th

e in

equ

alit

y sy

mbo

ls h

elp

you

rem

embe

rw

het

her

to

use

a d

ash

ed o

r so

lid

lin

e?U

se a

das

hed

lin

e if

th

e in

equ

alit

y sy

mb

ol i

s �

or

�,b

ecau

se t

hes

esy

mb

ols

do

no

t in

clu

de

equ

alit

y an

d t

he

das

hed

lin

e re

min

ds

you

th

atth

e lin

e it

self

is n

ot

incl

ud

ed in

th

e g

rap

h.U

se a

so

lid li

ne

if t

he

sym

bo

lis

�o

r

,bec

ause

th

ese

sym

bo

ls in

clu

de

equ

alit

y an

d t

ell y

ou

th

at t

he

line

itse

lf is

incl

ud

ed in

th

e g

rap

h.

x

y

O

Exam

ple

Stud

y G

uide

and

Inte

rven

tion

So

lvin

g S

yste

ms

of

Ineq

ual

itie

s by

Gra

ph

ing

Lesson 3-3

Cha

pter

321

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-3

Copyright ©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Gra

ph

Sys

tem

s o

f In

equ

alit

ies

To s

olve

a s

yste

m o

f in

equa

litie

s,gr

aph

the

ineq

ualit

ies

in t

he s

ame

coor

dina

te p

lane

.The

sol

utio

n se

t is

rep

rese

nted

by

the

inte

rsec

tion

of

the

grap

hs.

Sol

ve t

he

syst

em o

f in

equ

alit

ies

by

grap

hin

g.y

2x

�1

and

y�

�2

Th

e so

luti

on o

f y

�2x

�1

is R

egio

ns

1 an

d 2.

Th

e so

luti

on o

f y

��

2 is

Reg

ion

s 1

and

3.

Th

e in

ters

ecti

on o

f th

ese

regi

ons

is R

egio

n 1

,wh

ich

is

the

solu

tion

set

of

the

syst

em o

f in

equ

alit

ies.

Sol

ve e

ach

sys

tem

of

ineq

ual

itie

s b

y gr

aph

ing.

1.x

�y

�2

2.3x

�2y

��

13.

⏐y⏐

�1

x�

2y�

1x

�4y

��

12x

�2

4.y

��

35.

y�

�2

6.y

��

�1

y�

2xy

��

2x�

1y

�3x

�1

7.x

�y

�4

8.x

�3y

�3

9.x

�2y

�6

2x�

y�

2x

�2y

�4

x�

4y�

�4

x

y

Ox

y

O

x

y

O

x

y

Ox

y

O

x

y

O

x � 4x � 3

x � 2

x

y

Ox

y

Ox

y

O

x � 3

x � 3

x

y

O

Regi

on 3

Regi

on 1

Regi

on 2

Exer

cise

s

Answers (Lesson 3-3)

A1-A19 A2-03-873973 5/22/06 8:25 AM Page A9

Page 10: Answers (Lesson 3-1) · A system of equations is a set of two or more equations containing the same variables. You can solve a system of linear equations by graphing the equations

Chapter 3 A10 Glencoe Algebra 2

Exam

ple

Cha

pter

322

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-3

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Fin

d V

erti

ces

of

a Po

lyg

on

al R

egio

nS

omet

imes

th

e gr

aph

of

a sy

stem

of

ineq

ual

itie

s fo

rms

a bo

un

ded

regi

on.Y

ou c

an f

ind

the

vert

ices

of

the

regi

on b

y a

com

bin

atio

nof

th

e m

eth

ods

use

d ea

rlie

r in

th

is c

hap

ter:

grap

hin

g,su

bsti

tuti

on,a

nd/

or e

lim

inat

ion

.

Fin

d t

he

coor

din

ates

of

the

vert

ices

of

the

figu

re f

orm

ed b

y 5x

�4y

�20

,y�

2x�

3,an

d x

�3y

�4.

Gra

ph t

he

bou

nda

ry o

f ea

ch i

neq

ual

ity.

Th

e in

ters

ecti

ons

of t

he

bou

nda

ry l

ines

are

th

e ve

rtic

es o

f a

tria

ngl

e.T

he

vert

ex (

4,0)

can

be

dete

rmin

ed f

rom

th

e gr

aph

.To

fin

d th

eco

ordi

nat

es o

f th

e se

con

d an

d th

ird

vert

ices

,sol

ve t

he

two

syst

ems

of e

quat

ion

s

y�

2x�

3an

dy

�2x

�3

5x�

4y�

20x

�3y

�4

x

y

O

Stud

y G

uide

and

Inte

rven

tion

(co

ntin

ued)

So

lvin

g S

yste

ms

of

Ineq

ual

itie

s by

Gra

ph

ing

For

th

e fi

rst

syst

em o

f eq

uat

ion

s,re

wri

te t

he

firs

teq

uat

ion

in

sta

nda

rd f

orm

as

2x�

y�

�3.

Th

enm

ult

iply

th

at e

quat

ion

by

4 an

d ad

d to

th

e se

con

deq

uat

ion

.2x

�y

��

3M

ultip

ly b

y 4.

8x�

4y�

�12

5x�

4y�

20(�

)5x

�4y

�20

13x

�8

x�

Th

en s

ubs

titu

te x

�in

on

e of

th

e or

igin

al e

quat

ion

s an

d so

lve

for

y.

2 ���

y�

�3

�y

��

3

y�

Th

e co

ordi

nat

es o

f th

e se

con

d ve

rtex

are

�,4

�.3 � 13

8 � 13

55 � 13

16 � 138 � 13

8 � 13

8 � 13

For

th

e se

con

d sy

stem

of

equ

atio

ns,

use

su

bsti

tuti

on.

Su

bsti

tute

2x

�3

for

yin

th

ese

con

d eq

uat

ion

to

get

x�

3(2x

�3)

�4

x�

6x�

9 �

4�

5x�

13x

��

Th

en s

ubs

titu

te x

��

in t

he

firs

t eq

uat

ion

to

solv

e fo

r y.

y�

2 ����

3

y�

��

3

y�

Th

e co

ordi

nat

es o

f th

e th

ird

vert

ex a

re ��

2,�

2�.

1 � 53 � 5

11 � 526 � 5

13 � 5

13 � 5

13 � 5

Th

us,

the

coor

din

ates

of

the

thre

e ve

rtic

es a

re (

4,0)

, �,4

�,an

d ��2

,�2

�.

Fin

d t

he

coor

din

ates

of

the

vert

ices

of

the

figu

re f

orm

ed b

y ea

ch s

yste

m o

fin

equ

alit

ies.

1.y

��

3x�

72.

x�

�3

3.y

��

x�

3

y�

x(2

,1),

(�4,

�2)

,y

��

x�

3(�

3,4)

,y

�x

�1

(�2,

4),(

2,2)

,y

��

2(3

,�2)

y�

x�

1(�

3,�

4),(

3,2)

y�

3x�

10��

3,�

�4 � 5

3 � 5

1 � 2

1 � 31 � 2

1 � 2

1 � 53 � 5

3 � 138 � 13

Exer

cise

s

Skill

s Pr

acti

ceS

olv

ing

Sys

tem

s o

f In

equ

alit

ies

by G

rap

hin

g

Lesson 3-3

Cha

pter

323

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-3

Copyright ©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Sol

ve e

ach

sys

tem

of

ineq

ual

itie

s b

y gr

aph

ing.

1.x

�1

2.x

��

33.

x�

2y

��

1y

��

3x

�4

no

so

luti

on

4.y

�x

5.y

��

4x6.

x�

y�

�1

y�

�x

y�

3x�

23x

�y

�4

7.y

�3

8.y

��

2x�

39.

x�

y�

4x

�2y

�12

y�

x�

22x

�y

�4

Fin

d t

he

coor

din

ates

of

the

vert

ices

of

the

figu

re f

orm

ed b

y ea

ch s

yste

m o

fin

equ

alit

ies.

10.y

�0

11.y

�3

�x

12.x

��

2x

�0

y�

3y

�x

�2

y�

�x

�1

x�

�5

x�

y�

2 (�

2,4)

,(0

,0),

(0,�

1),(

�1,

0)(0

,3),

(�5,

3),(

�5,

8)(�

2,�

4),(

2,0)

x

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y

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y

O2

2

x

y

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y

O

x

y

Ox

y

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y

O

Answers (Lesson 3-3)

A1-A19 A2-03-873973 5/22/06 8:25 AM Page A10

Page 11: Answers (Lesson 3-1) · A system of equations is a set of two or more equations containing the same variables. You can solve a system of linear equations by graphing the equations

Chapter 3 A11 Glencoe Algebra 2

An

swer

s

Cha

pter

324

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-3

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Sol

ve e

ach

sys

tem

of

ineq

ual

itie

s b

y gr

aph

ing.

1.y

�1

��

x2.

x�

�2

3.y

�2x

�3

y�

12y

�3x

�6

y�

�x

�2

4.x

�y

��

25.

⏐y⏐

�1

6.3y

�4x

3x�

y�

�2

y�

x�

12x

�3y

��

6

Fin

d t

he

coor

din

ates

of

the

vert

ices

of

the

figu

re f

orm

ed b

y ea

ch s

yste

m o

fin

equ

alit

ies.

7.y

�1

�x

8.x

�y

�2

9.y

�2x

�2

y�

x�

1x

�y

�2

2x�

3y�

6x

�3

x�

�2

y�

4

(1,0

),(3

,2),

(3,�

2)(�

2,4)

,(�

2,�

4),(

2,0)

(�3,

4), �

,1�,(

3,4)

DR

AM

AF

or E

xerc

ises

10

and

11,

use

th

e fo

llow

ing

info

rmat

ion

.T

he

dram

a cl

ub

is s

elli

ng

tick

ets

to i

ts p

lay.

An

adu

lt t

icke

t co

sts

$15

and

a st

ude

nt

tick

et c

osts

$11

.Th

e au

dito

riu

m w

ill

seat

300

tic

ket-

hol

ders

.Th

e dr

ama

clu

b w

ants

to

coll

ect

atle

ast

$363

0 fr

om t

icke

t sa

les.

10.W

rite

an

d gr

aph

a s

yste

m o

f fo

ur

ineq

ual

itie

s th

at

desc

ribe

how

man

y of

eac

h t

ype

of t

icke

t th

e cl

ub

mu

st

sell

to

mee

ts i

ts g

oal.

x�

0,y

�0,

x�

y

300,

15x

�11

y�

3630

11.L

ist

thre

e di

ffer

ent

com

bin

atio

ns

of t

icke

ts s

old

that

sati

sfy

the

ineq

ual

itie

s.S

amp

le a

nsw

er:

250

adu

lt a

nd

50

stu

den

t,20

0 ad

ult

an

d

100

stu

den

t,14

5 ad

ult

an

d 1

48 s

tud

ent

Pla

y T

ickets

Ad

ult

Tic

kets

Student Tickets

100

020

030

040

0

400

350

300

250

200

150

100 50

3 � 2

x

y O

y

xO

y

xO

x

y

Ox

y

Ox

y

O

1 � 2

Prac

tice

S

olv

ing

Sys

tem

s o

f In

equ

alit

ies

by G

rap

hin

g

Lesson 3-3

Cha

pter

325

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-3

Copyright ©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Wor

d Pr

oble

m P

ract

ice

So

lvin

g S

yste

ms

of

Ineq

ual

itie

s by

Gra

ph

ing

1.B

IRD

BA

THM

elis

sa w

ants

to

put

a bi

rdba

th i

n h

er y

ard

at p

oin

t (x

,y),

and

wan

ts i

t to

be

is i

nsi

de t

he

encl

osed

shad

ed a

rea

show

n i

n t

he

grap

h.

Fir

st,s

he

chec

ks t

hat

x�

�3

and

y�

�2.

Wh

at l

inea

r in

equ

alit

y m

ust

sh

ech

eck

to c

oncl

ude

th

at (

x,y)

is

insi

de t

he

tria

ngl

e?x

� y

3

2.SQ

UA

RES

M

att

fin

ds a

blo

t of

in

kco

veri

ng

his

wri

tin

g in

his

not

es f

orm

ath

cla

ss.H

e se

es “A

squ

are

is d

efin

edby

|x|

�8

and

_”.W

rite

an

in

equ

alit

yth

at c

ompl

etes

th

is s

ente

nce

.

A sq

uare

is d

efin

ed b

y |x

| , 8

and

Sam

ple

an

swer

:|y

| 8.

3.H

OLI

DA

YA

man

da r

ecei

ved

pres

ents

and

card

s fr

om f

rien

ds o

ver

the

hol

iday

seas

on.E

very

pre

sen

t ca

me

wit

h o

ne

card

an

d n

one

of h

er f

rien

ds s

ent

her

mor

e th

an o

ne

card

.Les

s th

an 1

0 of

her

frie

nds

sen

t on

ly a

car

d.D

escr

ibe

this

situ

atio

n u

sin

g in

equ

alit

ies.

Let

pb

e th

e n

um

ber

of

pre

sen

tsan

d c

be

the

nu

mb

er o

f ca

rds.

p

can

d c

�p

�10

4.D

ECK

Th

e W

righ

ts a

re b

uil

din

g a

deck

.T

he

deck

is

defi

ned

by

the

ineq

ual

itie

s x

�5,

0.25

x�

y�

�4.

75,y

�5,

and

4.5x

�y

��

17.5

.Gra

ph t

he

ineq

ual

itie

s an

d fi

nd

the

coor

din

ates

of

th

e de

ck’s

cor

ner

s?

(5,5

),(�

5,5)

,(5,

�6)

,(�

3,�

4)TI

CK

ETS

For

Exe

rcis

es 5

an

d 6

,use

th

efo

llow

ing

info

rmat

ion

.A

th

eate

r ch

arge

s $1

0 fo

r ad

ult

s an

d $5

for

chil

dren

12

or u

nde

r.T

he

thea

ter

mak

es a

prof

it i

f th

ey c

an s

ell

mor

e th

an $

600

wor

thof

tic

kets

.Th

e th

eate

r h

as s

eati

ng

for

100

peop

le.

5.W

rite

a s

yste

m o

f li

nea

r in

equ

alit

ies

that

des

crib

es t

he

situ

atio

n.

Let

Ab

e th

e n

um

ber

of

adu

lts

and

Cb

e th

e n

um

ber

of

child

ren

:A

�0,

C�

0,A

�C

10

0,10

A�

5C�

600.

6.G

raph

th

e so

luti

on t

o th

e in

equ

alit

ies.

Can

th

e th

eate

r m

ake

a pr

ofit

if

no

adu

lts

com

e to

th

e pe

rfor

man

ce?

no

A

CO

100

100 50

50

y

xO

5

5

-5

-5

y

xO

5

5

-5

Answers (Lesson 3-3)

A1-A19 A2-03-873973 5/22/06 8:25 AM Page A11

Page 12: Answers (Lesson 3-1) · A system of equations is a set of two or more equations containing the same variables. You can solve a system of linear equations by graphing the equations

Chapter 3 A12 Glencoe Algebra 2

Cha

pter

326

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-3

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Enri

chm

ent

Cre

ativ

e D

esig

ns

A s

yste

m o

f li

nea

r in

equ

alit

ies

can

be

use

d to

def

ine

the

regi

on b

oun

ded

by a

geo

met

ric

shap

e gr

aph

ed o

n a

coo

rdin

ate

plan

e.F

or e

xam

ple,

the

rect

angl

e sh

own

can

be

defi

ned

by

the

syst

em x�

4x

�0

y�

3y

�0.

Th

e tr

ian

gle

show

n c

an b

e de

scri

bed

usi

ng

the

ineq

ual

itie

s

x�

2y�

4x

�0

y�

1.

1.F

ind

a sy

stem

of

lin

ear

ineq

ual

itie

s to

des

crib

e th

e ar

ea b

oun

ded

by t

he

bow

tie

sh

ape

belo

w.T

he

inte

rsec

tion

poi

nts

are

(1,

1),(

1,4)

,(3,

3),(

5,2)

,an

d (5

,5).

if 1

x

3

if 3

x

5

y�

xan

dy

x

x�

2y

9x

�2y

�9

2.F

ind

a sy

stem

of

lin

ear

ineq

ual

itie

s to

des

crib

e th

e ar

ea b

oun

ded

by t

he

basi

c ‘h

ouse

’sh

ape

show

n b

elow

.Th

e in

ters

ecti

on p

oin

ts a

re (

1,1)

,(1,

5),(

3,7)

,(5,

5),a

nd

(5,1

).

x�

1x

5

y

x�

4y

x�

10y

� 1

y

xO

y

xO

y

xO

y

xO

Lesson 3-3

Cha

pter

327

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-4

Copyright ©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Less

on R

eadi

ng G

uide

Lin

ear

Pro

gra

mm

ing

Get

Rea

dy

for

the

Less

on

Rea

d t

he

intr

odu

ctio

n t

o L

esso

n 3

-4 i

n y

our

text

boo

k.

Nam

e tw

o or

mor

e fa

cts

that

in

dica

te t

hat

you

wil

l n

eed

to u

se i

neq

ual

itie

s to

mod

el

this

sit

uat

ion

.S

amp

le a

nsw

er:T

he

buoy

ten

der

can

car

ry u

p t

o 8

new

bu

oys.

Th

ere

seem

sto

be

a lim

it o

f 24

ho

urs

on

th

e ti

me

the

crew

has

at

sea.

Th

e cr

ew w

ill w

ant

to r

epai

r o

r re

pla

ce t

he

max

imu

m n

um

ber

of

buoy

s p

oss

ible

.

Rea

d t

he

Less

on

1.C

ompl

ete

each

sen

ten

ce.

a.W

hen

you

fin

d th

e fe

asib

le r

egio

n f

or a

lin

ear

prog

ram

min

g pr

oble

m,y

ou a

re s

olvi

ng

a sy

stem

of

lin

ear

call

ed

.Th

e po

ints

in t

he

feas

ible

reg

ion

are

of

th

e sy

stem

.

b.

Th

e co

rner

poi

nts

of

a po

lygo

nal

reg

ion

are

th

e of

th

e fe

asib

le r

egio

n.

2.A

pol

ygon

al r

egio

n a

lway

s ta

kes

up

only

a l

imit

ed p

art

of t

he

coor

din

ate

plan

e.O

ne

way

to t

hin

k of

th

is i

s to

im

agin

e a

circ

le o

r re

ctan

gle

that

th

e re

gion

wou

ld f

it i

nsi

de.I

n t

he

case

of

a po

lygo

nal

reg

ion

,you

can

alw

ays

fin

d a

circ

le o

r re

ctan

gle

that

is

larg

e en

ough

to c

onta

in a

ll t

he

poin

ts o

f th

e po

lygo

nal

reg

ion

.Wh

at w

ord

is u

sed

to d

escr

ibe

a re

gion

that

can

be

encl

osed

in

th

is w

ay?

Wh

at w

ord

is u

sed

to d

escr

ibe

a re

gion

th

at i

s to

o la

rge

to b

e en

clos

ed i

n t

his

way

?b

ou

nd

ed;

un

bo

un

ded

3.H

ow d

o yo

u f

ind

the

corn

er p

oin

ts o

f th

e po

lygo

nal

reg

ion

in

a l

inea

r pr

ogra

mm

ing

prob

lem

?Yo

u s

olv

e a

syst

em o

f tw

o li

nea

r eq

uat

ion

s.

4.W

hat

are

som

e ev

eryd

ay m

ean

ings

of

the

wor

d fe

asib

leth

at r

emin

d yo

u o

f th

em

ath

emat

ical

mea

nin

g of

th

e te

rm f

easi

ble

regi

on?

Sam

ple

an

swer

:p

oss

ible

or

ach

ieva

ble

Rem

emb

er W

hat

Yo

u L

earn

ed

5.L

ook

up

the

wor

d co

nst

rain

tin

a d

icti

onar

y.If

mor

e th

an o

ne

defi

nit

ion

is

give

n,c

hoo

seth

e on

e th

at s

eem

s cl

oses

t to

th

e id

ea o

f a

con

stra

int

in a

lin

ear

prog

ram

min

g pr

oble

m.

How

can

th

is d

efin

itio

n h

elp

you

to

rem

embe

r th

e m

ean

ing

of c

onst

rain

tas

it

is u

sed

inth

is l

esso

n?

Sam

ple

an

swer

:A

co

nst

rain

tis

a r

estr

icti

on

or

limit

atio

n.T

he

con

stra

ints

in a

lin

ear

pro

gra

mm

ing

pro

ble

m a

re r

estr

icti

on

s o

n t

he

vari

able

s th

at t

ran

slat

e in

to in

equ

alit

y st

atem

ents

.

vert

ices

solu

tio

ns

con

stra

ints

ineq

ual

itie

s

Answers (Lessons 3-3 and 3-4)

A1-A19 A2-03-873973 5/22/06 8:25 AM Page A12

Page 13: Answers (Lesson 3-1) · A system of equations is a set of two or more equations containing the same variables. You can solve a system of linear equations by graphing the equations

Chapter 3 A13 Glencoe Algebra 2

An

swer

s

Cha

pter

328

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-4

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Stud

y G

uide

and

Inte

rven

tion

Lin

ear

Pro

gra

mm

ing

Max

imu

m a

nd

Min

imu

m V

alu

esW

hen

a s

yste

m o

f li

nea

r in

equ

alit

ies

prod

uce

s a

bou

nde

d po

lygo

nal

reg

ion

,th

e m

axim

um

or m

inim

um

valu

e of

a r

elat

ed f

un

ctio

n w

ill

occu

rat

a v

erte

x of

th

e re

gion

.

Gra

ph

th

e sy

stem

of

ineq

ual

itie

s.N

ame

the

coor

din

ates

of

the

vert

ices

of

the

feas

ible

reg

ion

.Fin

d t

he

max

imu

m a

nd

min

imu

m v

alu

es o

f th

efu

nct

ion

f(x

,y)

�3x

�2y

for

this

pol

ygon

al r

egio

n.

y

4y

x�

6

y�

x�

y

6x�

4F

irst

fin

d th

e ve

rtic

es o

f th

e bo

un

ded

regi

on.G

raph

th

e in

equ

alit

ies.

Th

e po

lygo

n f

orm

ed i

s a

quad

rila

tera

l w

ith

ver

tice

s at

(0

,4),

(2,4

),(5

,1),

and

(�1,

�2)

.Use

th

e ta

ble

to f

ind

the

max

imu

m a

nd

min

imu

m v

alu

es o

f f(

x,y)

�3x

�2y

.

Th

e m

axim

um

val

ue

is 1

7 at

(5,

1).T

he

min

imu

m v

alu

e is

�7

at (

�1,

�2)

.

Gra

ph

eac

h s

yste

m o

f in

equ

alit

ies.

Nam

e th

e co

ord

inat

es o

f th

e ve

rtic

es o

f th

efe

asib

le r

egio

n.F

ind

th

e m

axim

um

an

d m

inim

um

val

ues

of

the

give

n f

un

ctio

n f

orth

is r

egio

n.

1.y

�2

2.y

��

23.

x�

y�

21

�x

�5

y�

2x�

44y

�x

�8

y�

x�

3x

�2y

��

1y

�2x

�5

f(x,

y) �

3x�

2yf(

x,y)

�4x

�y

f(x,

y) �

4x�

3y

vert

ices

:(1

,2),

(1,4

),ve

rtic

es:

(�5,

�2)

,ve

rtic

es (

0,2)

,(4,

3),

(5,8

),(5

,2);

max

:11

;(3

,2),

(1,�

2);

�,�

�;m

ax:

25;

min

:6

m

in;

�5

max

:10

;m

in:

�18

1 � 37 � 3

x

y

Ox

y

O

x

y

O

(x,y

)3x

�2y

f(x,

y)

(0,

4)3(

0) �

2(4)

8

(2,

4)3(

2) �

2(4)

14

(5,

1)3(

5) �

2(1)

17

(�1,

�2)

3(�

1) �

2(�

2)�

7

x

y O

3 � 21 � 2

Exam

ple

Exer

cise

s

Exam

ple

Lesson 3-4

Cha

pter

329

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-4

Copyright ©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Rea

l-W

orl

d P

rob

lem

sW

hen

sol

vin

g li

nea

r p

rogr

amm

ing

prob

lem

s,u

se t

he

foll

owin

g pr

oced

ure

.

1.D

efin

e va

riab

les.

2.W

rite

a s

yste

m o

f in

equ

alit

ies.

3.G

raph

th

e sy

stem

of

ineq

ual

itie

s.4.

Fin

d th

e co

ordi

nat

es o

f th

e ve

rtic

es o

f th

e fe

asib

le r

egio

n.

5.W

rite

an

exp

ress

ion

to

be m

axim

ized

or

min

imiz

ed.

6.S

ubs

titu

te t

he

coor

din

ates

of

the

vert

ices

in

th

e ex

pres

sion

.7.

Sel

ect

the

grea

test

or

leas

t re

sult

to

answ

er t

he

prob

lem

.

A p

ain

ter

has

exa

ctly

32

un

its

of y

ello

w d

ye a

nd

54

un

its

of g

reen

dye

.He

pla

ns

to m

ix a

s m

any

gall

ons

as p

ossi

ble

of

colo

r A

an

d c

olor

B.E

ach

gall

on o

f co

lor

A r

equ

ires

4 u

nit

s of

yel

low

dye

an

d 1

un

it o

f gr

een

dye

.Eac

hga

llon

of

colo

r B

req

uir

es 1

un

it o

f ye

llow

dye

an

d 6

un

its

of g

reen

dye

.Fin

d t

he

max

imu

m n

um

ber

of

gall

ons

he

can

mix

.

Ste

p 1

Def

ine

the

vari

able

s.x

�th

e n

um

ber

of g

allo

ns

of c

olor

A m

ade

y�

the

nu

mbe

r of

gal

lon

s of

col

or B

mad

e

Ste

p 2

Wri

te a

sys

tem

of

ineq

ual

itie

s.S

ince

th

e n

um

ber

of g

allo

ns

mad

e ca

nn

ot b

en

egat

ive,

x�

0 an

d y

�0.

Th

ere

are

32 u

nit

s of

yel

low

dye

;eac

h g

allo

n o

f co

lor

A r

equ

ires

4 u

nit

s,an

d ea

ch g

allo

n o

f co

lor

B r

equ

ires

1 u

nit

.S

o 4x

�y

�32

.S

imil

arly

for

th

e gr

een

dye

,x�

6y�

54.

Ste

ps

3 an

d 4

Gra

ph t

he

syst

em o

f in

equ

alit

ies

and

fin

d th

e co

ordi

nat

es o

f th

e ve

rtic

es o

fth

e fe

asib

le r

egio

n.T

he

vert

ices

of

the

feas

ible

reg

ion

are

(0,

0),(

0,9)

,(6,

8),a

nd

(8,0

).S

tep

s 5–

7F

ind

the

max

imu

m n

um

ber

of g

allo

ns,

x�

y,th

at h

e ca

n m

ake.

Th

e m

axim

um

nu

mbe

r of

gal

lon

s th

e pa

inte

r ca

n m

ake

is 1

4,6

gall

ons

of c

olor

A a

nd

8 ga

llon

s of

col

or B

.

1.FO

OD

A d

elic

ates

sen

has

12

pou

nds

of

plai

n s

ausa

ge a

nd

10 p

oun

ds o

f sp

icy

sau

sage

.

A p

oun

d of

Bra

twu

rst

A c

onta

ins

pou

nd

of p

lain

sau

sage

an

d po

un

d of

spi

cy

sau

sage

.A p

oun

d of

Bra

twu

rst

B c

onta

ins

pou

nd

of e

ach

sau

sage

.

Fin

d th

e m

axim

um

nu

mbe

r of

pou

nds

of

brat

wu

rst

that

can

be

mad

e.4

po

un

ds

of

Bra

twu

rst

A a

nd

18

po

un

ds

of

Bra

twu

rst

B

2.M

AN

UFA

CTU

RIN

GM

ach

ine

A c

an p

rodu

ce 3

0 st

eeri

ng

wh

eels

per

hou

r at

a c

ost

of $

8pe

r h

our.

Mac

hin

e B

can

pro

duce

40

stee

rin

g w

hee

ls p

er h

our

at a

cos

t of

$12

per

hou

r.T

he

com

pan

y ca

n u

se e

ith

er m

ach

ine

by i

tsel

f or

bot

h m

ach

ines

at

the

sam

e ti

me.

Wh

atis

th

e m

inim

um

nu

mbe

r of

hou

rs n

eede

d to

pro

duce

380

ste

erin

g w

hee

ls i

f th

e co

st m

ust

be n

o m

ore

than

$10

8?6

ho

urs

;6

ho

urs

on

Mac

hin

e A

an

d 5

ho

urs

on

Mac

hin

e B

sim

ult

aneo

usl

y

1 � 2

1 � 43 � 4

Co

lor

A (

gal

lon

s)

Color B (gallons)

510

1520

2530

3540

4550

550

40 35 30 25 20 15 10 5

( 6, 8

)

( 8, 0

)( 0

, 9)

Stud

y G

uide

and

Inte

rven

tion

(co

ntin

ued)

Lin

ear

Pro

gra

mm

ing

Exer

cise

s

Answers (Lesson 3-4)

A1-A19 A2-03-873973 5/22/06 8:25 AM Page A13

Page 14: Answers (Lesson 3-1) · A system of equations is a set of two or more equations containing the same variables. You can solve a system of linear equations by graphing the equations

Chapter 3 A14 Glencoe Algebra 2

Gra

ph

eac

h s

yste

m o

f in

equ

alit

ies.

Nam

e th

e co

ord

inat

es o

f th

e ve

rtic

es o

f th

efe

asib

le r

egio

n.F

ind

th

e m

axim

um

an

d m

inim

um

val

ues

of

the

give

n f

un

ctio

n f

orth

is r

egio

n.

1.x

�2

2.x

�1

3.x

�0

x�

5y

�6

y�

0y

�1

y�

x�

2y

�7

�x

y�

4f(

x,y)

�x

�y

f(x,

y) �

3x�

yf(

x,y)

�x

�y

max

.:9,

min

.:3

max

.:2,

min

.:�

5m

ax.:

21,m

in.:

0

4.x

��

15.

y�

2x6.

y�

�x

�2

x�

y�

6y

�6

�x

y�

3x�

2f(

x,y)

�x

�2y

y�

6y

�x

�4

f(x,

y) �

4x�

3yf(

x,y)

��

3x�

5y

max

.:13

,no

min

.n

o m

ax.,

min

.:20

max

.:22

,min

.:�

2

7.M

AN

UFA

CTU

RIN

GA

bac

kpac

k m

anu

fact

ure

r pr

odu

ces

an i

nte

rnal

fra

me

pack

an

d an

exte

rnal

fra

me

pack

.Let

xre

pres

ent

the

nu

mbe

r of

in

tern

al f

ram

e pa

cks

prod

uce

d in

one

hou

r an

d le

t y

repr

esen

t th

e n

um

ber

of e

xter

nal

fra

me

pack

s pr

odu

ced

in o

ne

hou

r.T

hen

th

e in

equ

alit

ies

x�

3y�

18,2

x�

y�

16,x

�0,

and

y�

0 de

scri

be t

he

con

stra

ints

for

man

ufa

ctu

rin

g bo

th p

acks

.Use

th

e pr

ofit

fu

nct

ion

f(x

) �

50x

�80

yan

d th

eco

nst

rain

ts g

iven

to

dete

rmin

e th

e m

axim

um

pro

fit

for

man

ufa

ctu

rin

g bo

th b

ackp

acks

for

the

give

n c

onst

rain

ts.

$620

( 1, 5

)

( –1,

–1)

( –3,

1)

x

y

O

( 3, 6

)

( 2, 4

)

x

y

O

( –1,

7)

x

y

O

x

y

O

( 0, 7

)

( 0, 0

)( 7

, 0)

x

y

O

( 1, 6

)

( 1, –

1)

( 8, 6

)

x

y

O

( 2, 4

)

( 2, 1

)( 5

, 1)

( 5, 4

)

Cha

pter

330

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-4

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Skill

s Pr

acti

ceL

inea

r P

rog

ram

min

g

3-4

Lesson 3-4

Cha

pter

331

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-4

Copyright ©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Gra

ph

eac

h s

yste

m o

f in

equ

alit

ies.

Nam

e th

e co

ord

inat

es o

f th

e ve

rtic

es o

f th

efe

asib

le r

egio

n.F

ind

th

e m

axim

um

an

d m

inim

um

val

ues

of

the

give

n f

un

ctio

n f

orth

is r

egio

n.

1.2x

�4

�y

2.3x

�y

�7

3.x

�0

�2x

�4

�y

2x�

y�

3y

�0

y�

2y

�x

�3

y�

6f(

x,y)

��

2x�

yf(

x,y)

�x

�4y

y�

�3x

�15

f(x,

y) �

3x�

y

max

.:8,

min

.:�

4m

ax.:

12,m

in.:

�16

max

.:15

,min

.:0

4.x

�0

5.y

�3x

�6

6.2x

�3y

�6

y�

04y

�3x

�3

2x�

y�

24x

�y

��

7x

��

2x

�0

f(x,

y) �

�x

�4y

f(x,

y) �

�x

�3y

y�

0f(

x,y)

�x

�4y

�3

max

.:28

,min

.:0

max

.:,n

o m

in.

no

max

.,m

in.:

PRO

DU

CTI

ON

For

Exe

rcis

es 7

–9,u

se t

he

foll

owin

g in

form

atio

n.

A g

lass

blo

wer

can

for

m 8

sim

ple

vase

s or

2 e

labo

rate

vas

es i

n a

n h

our.

In a

wor

k sh

ift

of n

om

ore

than

8 h

ours

,th

e w

orke

r m

ust

for

m a

t le

ast

40 v

ases

.

7.L

et s

repr

esen

t th

e h

ours

for

min

g si

mpl

e va

ses

and

eth

e h

ours

for

min

g el

abor

ate

vase

s.W

rite

a s

yste

m o

f in

equ

alit

ies

invo

lvin

g th

e ti

me

spen

t on

eac

h t

ype

of v

ase.

s�

0,e

�0,

s �

e

8,8s

�2e

�40

8.If

th

e gl

ass

blow

er m

akes

a p

rofi

t of

$30

per

hou

r w

orke

d on

th

e si

mpl

e va

ses

and

$35

per

hou

r w

orke

d on

th

e el

abor

ate

vase

s,w

rite

a f

un

ctio

n f

or t

he

tota

l pr

ofit

on

th

e va

ses.

f(s,

e) �

30s

�35

e

9.F

ind

the

nu

mbe

r of

hou

rs t

he

wor

ker

shou

ld s

pen

d on

eac

h t

ype

of v

ase

to m

axim

ize

prof

it.W

hat

is

that

pro

fit?

4 h

on

eac

h;

$260

17 � 234 � 5

x

y

O

(3 – 2, 1)

( 0, 2

)

x

y O

(–7 – 5, 9 – 5)

( –2,

0)

x

y

O(–

7 – 4, 0)

( 0, 0

)

( 0, –

7)

( 3, 6

)

( 5, 0

)

( 0, 6

)

( 0, 0

)x

y

O

( 2, –

1)

( 4, 5

)

( 0, –

3)

x

y

O

( –3,

2)

( 3, 2

)

( 0, –

4)

x

y

OPrac

tice

L

inea

r P

rog

ram

min

g

Answers (Lesson 3-4)

A1-A19 A2-03-873973 5/22/06 8:25 AM Page A14

Page 15: Answers (Lesson 3-1) · A system of equations is a set of two or more equations containing the same variables. You can solve a system of linear equations by graphing the equations

Chapter 3 A15 Glencoe Algebra 2

An

swer

s

Wor

d Pr

oble

m P

ract

ice

Lin

ear

Pro

gra

mm

ing

Cha

pter

332

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-4

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

1.R

EGIO

NS

A r

egio

n i

n t

he

plan

e is

form

ed b

y th

e eq

uat

ion

s x

�y

�3,

x�

y�

�3,

and

x�

y�

�3.

Is t

his

regi

on b

oun

ded

or u

nbo

un

ded?

Exp

lain

.T

he

reg

ion

is u

nb

ou

nd

edb

ecau

se it

is o

pen

.Th

e p

oin

ts

(n,n

) ar

e in

th

e re

gio

n f

or

all

po

siti

ve v

alu

es o

f n

.

2.M

AN

UFA

CTU

RIN

GE

igh

ty w

orke

rsar

e av

aila

ble

to a

ssem

ble

tabl

es a

nd

chai

rs.I

t ta

kes

5 pe

ople

to

asse

mbl

e a

tabl

e an

d 3

peop

le t

o as

sem

ble

a ch

air.

Th

e w

orke

rs a

lway

s m

ake

at l

east

as

man

y ta

bles

as

chai

rs b

ecau

se t

he

tabl

esar

e ea

sier

to

mak

e.If

xis

th

e n

um

ber

ofta

bles

an

d y

is t

he

nu

mbe

r of

ch

airs

,th

esy

stem

of

ineq

ual

itie

s th

at r

epre

sen

tw

hat

can

be

asse

mbl

ed i

s x

�0,

y�

0,y

�x,

and

5x�

3y�

80.W

hat

is

the

max

imu

m t

otal

nu

mbe

r of

ch

airs

an

dta

bles

th

e w

orke

rs c

an m

ake?

10 t

able

s an

d 1

0 ch

airs

3.FI

SHA

n a

quar

ium

is

2000

cu

bic

inch

es.

Nat

han

wan

ts t

o po

pula

te t

he

aqu

ariu

mw

ith

neo

n t

etra

s an

d ca

tfis

h.I

t is

reco

mm

ende

d th

at e

ach

neo

n t

etra

be

allo

wed

50

cubi

c in

ches

an

d ea

ch c

atfi

shbe

all

owed

200

cu

bic

inch

es o

f sp

ace.

Nat

han

wou

ld l

ike

at l

east

on

e ca

tfis

hfo

r ev

ery

4 n

eon

tet

ras.

Let

nbe

th

en

um

ber

of n

eon

tet

ra a

nd

cbe

th

en

um

ber

of c

atfi

sh.T

he

foll

owin

gin

equ

alit

ies

form

th

e fe

asib

le r

egio

n f

orth

is s

itu

atio

n:n

�0,

c�

0,4c

�n

,an

d50

n�

200c

�20

00.W

hat

is

the

max

imu

m n

um

ber

of f

ish

Nat

han

can

put

in h

is a

quar

ium

?20

�5

�25

4.EL

EVA

TIO

N A

tra

pezo

idal

par

k is

bu

ilt

on a

sli

ght

incl

ine.

Th

e fu

nct

ion

for

th

egr

oun

d el

evat

ion

abo

ve s

ea l

evel

is

f(x,

y) �

x�

3y�

20 f

eet.

Wh

at a

re t

he

coor

din

ates

of

the

hig

hes

t po

int

in t

he

park

?

(5,2

)

CER

AM

ICS

For

Exe

rcis

es 5

–7,u

se t

he

foll

owin

g in

form

atio

n.

Josh

has

8 d

ays

to m

ake

pots

an

d pl

ates

to

sell

at

a lo

cal

fair

.Eac

h p

ot w

eigh

s 2

pou

nds

and

each

pla

te w

eigh

s 1

pou

nd.

Josh

can

not

carr

y m

ore

than

50

pou

nds

to

the

fair

.Eac

hda

y,h

e ca

n m

ake

at m

ost

5 pl

ates

an

d at

mos

t 3

pots

.He

wil

l m

ake

$12

prof

it f

orev

ery

plat

e an

d $2

5 pr

ofit

for

eve

ry p

ot t

hat

he

sell

s.

5.W

rite

lin

ear

ineq

ual

itie

s to

rep

rese

nt

the

nu

mbe

r of

pot

s p

and

plat

es a

Josh

may

bri

ng

to t

he

fair

.a

�0,

p�

0,2p

�a

50

,a

40,

and

p

24.

6.L

ist

the

coor

din

ates

of

the

vert

ices

of

the

feas

ible

reg

ion

.(0

,0),

(0,2

4),(

40,0

),(2

,24)

,(4

0,5)

wh

ere

the

ho

rizo

nta

l axi

sis

tak

en t

o r

epre

sen

t a

7.H

ow m

any

pots

an

d h

ow m

any

plat

essh

ould

Jos

h m

ake

to m

axim

ize

his

pote

nti

al p

rofi

t?2

pla

tes

and

24

po

ts

y

xO

5

5

Enri

chm

ent

Cha

pter

333

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-4

Copyright ©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Lesson 3-4

Sen

siti

vity

An

alys

isA

lin

ear

prog

ram

min

g m

odel

has

spe

cifi

c ob

ject

ive

coef

fici

ents

.For

exa

mpl

e,if

th

e va

lue

of a

mod

el i

s fo

un

d by

2x

�3y

�5,

the

obje

ctiv

e co

effi

cien

ts a

re {

2,3}

.Wh

at i

f th

ese

coef

fici

ents

wer

e {2

.1,2

.9}

or {

2.5,

3.1}

? H

ow w

ould

th

ese

chan

ges

affe

ct t

he

opti

mal

lin

ear

prog

ram

valu

e? T

his

typ

e of

in

vest

igat

ion

is

call

ed s

ensi

tivi

ty a

nal

ysis

.

In g

ener

al,t

he

obje

ctiv

e fu

nct

ion

in

tw

o-va

riab

le l

inea

r pr

ogra

mm

ing

prob

lem

can

be

wri

tten

as:

max

imiz

e (o

r m

inim

ize)

Ax

�B

y�

C,s

ubj

ect

to a

set

of

con

stra

int

equ

atio

ns.

Ch

ange

s to

th

e pa

ram

eter

sA

and

Bco

uld

ch

ange

th

e sl

ope

of t

he

lin

e.T

his

ch

ange

of

slop

eco

uld

lea

d to

a c

han

ge i

n t

he

opti

mu

m s

olu

tion

to

a di

ffer

ent

corn

er p

oin

t (R

ecal

l,th

eop

tim

um

sol

uti

on o

ccu

rs a

t a

corn

er p

oin

t).

Th

ere

is a

ran

ge i

n t

he

slop

e va

lue

that

wil

l pr

odu

ce t

his

chan

ge,t

hu

s th

ere

is a

ran

ge o

f va

riat

ion

for

bot

h A

and

Bth

at w

ill

keep

th

e op

tim

al s

olu

tion

th

e sa

me

(see

gra

ph).

1.F

ind

the

slop

e of

Ax

�B

y�

Can

d ob

serv

e h

owch

ange

s to

th

e pa

ram

eter

s A

and

Bca

n c

han

ge t

he

slop

e of

th

e li

ne.

Th

e sl

op

e,m

,of

Ax

�B

y�

C is

m�

.

Con

sid

er t

he

Lin

ear

Pro

gram

min

g p

rob

lem

:

Max

imiz

e:C

�2x

�3y

,S

ubj

ect

to:

3x �

y�

21x

�y

�9

y�

xy

�4

Aft

er f

indi

ng

the

inte

rsec

tion

s an

d ev

alu

atin

g th

e ob

ject

ive

equ

atio

n,w

e fi

nd

the

max

imal

solu

tion

is

(5,4

).If

th

e ob

ject

ive

coef

fici

ents

are

ch

ange

d fr

om 2

an

d 3

to A

and

B,t

he

opti

mu

m s

olu

tion

wit

h r

emai

n a

t (5

,4)

wh

ile

the

slop

e re

mai

ns

betw

een

th

e sl

ope

of

x�

y�

9 an

d th

e sl

ope

of 3

x�

y�

21.I

f n

ot,t

hen

th

e n

ew o

ptim

al s

olu

tion

wil

l be

at

(4,4

) or

(6,

3).

2.E

xpre

ss t

he

rela

tion

ship

,th

e sl

ope

of t

he

obje

ctiv

e fu

nct

ion

is

betw

een

th

e sl

ope

of t

he

lin

e x

�y

�9

and

the

slop

e of

th

e li

ne

3x�

y�

21,a

lgeb

raic

ally

.

�3

�1

3.D

eter

min

e th

e ra

nge

on

Aif

Bre

mai

ns

equ

al t

o 3.

�9

A

3

A � B

�A

�B

(x,

y)(0

, 0)

(4,

4)(5

, 4)

(6,

3)(7

, 0)

C0

2022

2114

y

xO

Answers (Lesson 3-4)

A1-A19 A2-03-873973 5/22/06 8:25 AM Page A15

Page 16: Answers (Lesson 3-1) · A system of equations is a set of two or more equations containing the same variables. You can solve a system of linear equations by graphing the equations

Chapter 3 A16 Glencoe Algebra 2

Answers (Lessons 3-4 and 3-5)

Exam

ple

Cha

pter

334

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-4

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Gra

ph

th

e sy

stem

x�

3y�

�7,

5x�

y

13,x

�6y

��

9,3x

�2y

��

7,an

d f

(x,y

)�4x

�3y

.Fin

d t

he

coor

din

ates

of

the

feas

ible

regi

on.T

hen

fin

d t

he

max

imu

m a

nd

min

imu

m v

alu

es f

or t

he

syst

em.

Sol

ve e

ach

in

equ

alit

y fo

r y.

En

ter

each

bou

nda

ry e

quat

ion

in

th

e Y

�sc

reen

.Fin

d th

e ve

rtic

es o

f th

e fe

asib

le r

egio

n.T

hen

fin

d th

e va

lues

of f

(x,y

) to

det

erm

ine

the

max

imu

m a

nd

min

imu

m v

alu

es.

Key

stro

kes:

1 3

7 3

5 13

1

6 3

2 3

2 7

2 6

[CA

LC

] 5

[QU

IT]

[ {

]

[Y]

4 3

[Y]

[ }

]

[CA

LC

] 5

[QU

IT]

[EN

TR

Y]

[CA

LC

] 5

[QU

IT]

[EN

TR

Y]

[CA

LC

] 5

[QU

IT]

[EN

TR

Y]

.

The

max

imum

val

ue o

f the

sys

tem

is 1

8 an

d th

e m

inim

um v

alue

is�

10.

EN

TER

2nd

2nd

EN

TER

EN

TER

EN

TER

2nd

GR

AP

HE

NTE

R2n

d2n

dE

NTE

RE

NTE

R

EN

TER

2nd

GR

AP

HE

NTE

R2n

d

2nd

EN

TER

EN

TER

EN

TER

2nd

GR

AP

H

EN

TER

2nd

ALP

HA

—,

ALP

HA

,2n

d2n

dE

NTE

RE

NTE

RE

NTE

R2n

d

ZO

OM

)�

(+

)�

(E

NTE

R)

�(

—)

�(

(–)

EN

TER

+(–

)

EN

TER

)�

(+

)�

(Y

=Gra

phin

g Ca

lcul

ator

Act

ivit

yL

inea

r P

rog

ram

min

gA

gra

phin

g ca

lcu

lato

r ca

n s

tore

th

e x-

an

d y-

coor

din

ates

wh

en u

sin

g th

ein

ters

ect

com

man

d in

th

e [C

AL

C]

men

u.T

his

can

be

disp

laye

d on

th

eh

ome

scre

en a

nd

use

d to

eva

luat

e an

exp

ress

ion

wit

h x

and

yva

riab

les.

Th

ispr

oces

s is

use

ful i

n fi

ndin

g th

e ve

rtic

es o

f th

e fe

asib

le r

egio

n an

d de

term

inin

gth

e m

axim

um

or

min

imu

m v

alu

e fo

r f(

x,y)

.

[�10

, 10]

scl

:1 b

y [�

10, 1

0] s

cl:1

Gra

ph

eac

h s

yste

m.F

ind

th

e co

ord

inat

es o

f th

e ve

rtic

es o

f th

e fe

asib

lere

gion

.Th

en f

ind

th

e m

axim

um

an

d m

inim

um

val

ues

for

th

e sy

stem

.

1.2x

�3y

�6

2.y

�4x

�6

3.y

�16

�x

3x�

2y�

�4

x�

4y�

70

�2y

�17

5x�

y�

152x

�y

�7

2x�

3y�

11f(

x,y)

�x

�3y

x�

6y�

10y

�3x

�1

f(x,

y) �

2x�

yy

�2x

�13

y�

7 �

2 xf(

x,y)

�5x

�6y

[�10

, 10]

scl

:1 b

y [�

10, 1

0] s

cl: 1

[�10

, 10]

scl

:1 b

y [�

10, 1

0] s

cl: 1

[�10

, 10]

scl

:1 b

y [�

10, 1

0] s

cl: 1

(0,2

),(3

,0),

(2,5

);(�

1,2)

,(�

2,�

2),(

3,1)

,(5

.5,0

),(6

.5,0

),(7

.5,8

.5),

min

.�3,

max

.�17

(4,�

1);

min

.��

4,m

ax.�

9(1

.2,4

.6),

(2.5

,2),

(9.6

6,6.

33);

min

.�24

.5,m

ax.�

88.5

Exer

cise

s

Lesson 3-4

Cha

pter

335

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-5

Copyright ©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Less

on R

eadi

ng G

uide

So

lvin

g S

yste

ms

of

Eq

uat

ion

s in

Th

ree

Var

iab

les

Get

Rea

dy

for

the

Less

on

Rea

d t

he

intr

odu

ctio

n t

o L

esso

n 3

-5 i

n y

our

text

boo

k.

At

the

1960

Su

mm

er O

lym

pics

in

Rom

e,It

aly,

the

Un

ited

Sta

tes

won

71

med

als.

Th

e U

.S.

team

won

13

mor

e go

ld m

edal

s th

an s

ilve

r an

d 5

few

er b

ron

ze m

edal

s th

an s

ilve

r.U

sin

g th

esa

me

vari

able

s as

th

ose

in t

he

intr

odu

ctio

n,w

rite

a s

yste

m o

f eq

uat

ion

s th

at d

escr

ibes

th

em

edal

s w

on f

or t

he

1960

Oly

mpi

cs.

g�

s�

b�

71;

g�

s�

13;

b�

s�

5

Rea

d t

he

Less

on

1.T

he

plan

es f

or t

he

equ

atio

ns

in a

sys

tem

of

thre

e li

nea

r eq

uat

ion

s in

th

ree

vari

able

sde

term

ine

the

nu

mbe

r of

sol

uti

ons.

Mat

ch e

ach

gra

ph d

escr

ipti

on b

elow

wit

h t

he

desc

ript

ion

of

the

nu

mbe

r of

sol

uti

ons

of t

he

syst

em.(

Som

e of

th

e it

ems

on t

he

righ

t m

aybe

use

d m

ore

than

on

ce,a

nd

not

all

pos

sibl

e ty

pes

of g

raph

s ar

e li

sted

.)

a.th

ree

para

llel

pla

nes

I.

one

solu

tion

b.

thre

e pl

anes

th

at i

nte

rsec

t in

a l

ine

II.

no

solu

tion

s

c.th

ree

plan

es t

hat

in

ters

ect

in o

ne

poin

t II

I.in

fin

ite

solu

tion

s

d.

one

plan

e th

at r

epre

sen

ts a

ll t

hre

e eq

uat

ion

s

2.S

upp

ose

that

th

ree

clas

smat

es,M

oniq

ue,

Josh

,an

d L

illy

,are

stu

dyin

g fo

r a

quiz

on

th

isle

sson

.Th

ey w

ork

toge

ther

on

sol

vin

g a

syst

em o

f eq

uat

ion

s in

th

ree

vari

able

s,x,

y,an

dz,

foll

owin

g th

e al

gebr

aic

met

hod

sh

own

in

you

r te

xtbo

ok.T

hey

fir

st f

ind

that

z�

3,th

enth

at y

��

2,an

d fi

nal

ly t

hat

x�

�1.

Th

e st

ude

nts

agr

ee o

n t

hes

e va

lues

,bu

t di

sagr

eeon

how

to

wri

te t

he

solu

tion

.Her

e ar

e th

eir

answ

ers:

Mon

iqu

e:(3

,�2,

�1)

Josh

:(�

2,�

1,3)

Lil

ly:(

�1,

�2,

3)

a.H

ow d

o yo

u t

hin

k ea

ch s

tude

nt

deci

ded

on t

he

orde

r of

th

e n

um

bers

in

th

e or

dere

dtr

iple

?S

amp

le a

nsw

er:

Mo

niq

ue

arra

ng

ed t

he

valu

es in

th

e o

rder

inw

hic

h s

he

fou

nd

th

em.J

osh

arr

ang

ed t

hem

fro

m s

mal

lest

to

larg

est.

Lill

y ar

ran

ged

th

em in

alp

hab

etic

al o

rder

of

the

vari

able

s.

b.

Wh

ich

stu

den

t is

cor

rect

?L

illy

Rem

emb

er W

hat

Yo

u L

earn

ed

3.H

ow c

an y

ou r

emem

ber

that

obt

ain

ing

the

equ

atio

n 0

�0

indi

cate

s a

syst

em w

ith

infi

nit

ely

man

y so

luti

ons,

wh

ile

obta

inin

g an

equ

atio

n s

uch

as

0 �

8 in

dica

tes

a sy

stem

wit

h n

o so

luti

ons?

0 �

0 is

alw

ays

tru

e,w

hile

0 �

8 is

nev

er t

rue.

III

I

III

II

A1-A19 A2-03-873973 5/22/06 8:25 AM Page A16

Page 17: Answers (Lesson 3-1) · A system of equations is a set of two or more equations containing the same variables. You can solve a system of linear equations by graphing the equations

Chapter 3 A17 Glencoe Algebra 2

An

swer

s

Answers (Lesson 3-5)

Cha

pter

336

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-5

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Stud

y G

uide

and

Inte

rven

tion

So

lvin

g S

yste

ms

of

Eq

uat

ion

s in

Th

ree

Var

iab

les

Syst

ems

in T

hre

e V

aria

ble

sU

se t

he

met

hod

s u

sed

for

solv

ing

syst

ems

of l

inea

req

uat

ion

s in

tw

o va

riab

les

to s

olve

sys

tem

s of

equ

atio

ns

in t

hre

e va

riab

les.

A s

yste

m o

fth

ree

equ

atio

ns

in t

hre

e va

riab

les

can

hav

e a

un

iqu

e so

luti

on,i

nfi

nit

ely

man

y so

luti

ons,

orn

o so

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s

Exam

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Lesson 3-5

Cha

pter

337

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-5

Copyright ©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Rea

l-W

orl

d P

rob

lem

s

Th

e L

ared

o S

por

ts S

hop

sol

d 1

0 b

alls

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ats,

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2 b

ases

for

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on M

ond

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ues

day

th

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old

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nes

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th

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hat

are

th

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e

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ch p

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A1-A19 A2-03-873973 5/22/06 8:25 AM Page A17

Page 18: Answers (Lesson 3-1) · A system of equations is a set of two or more equations containing the same variables. You can solve a system of linear equations by graphing the equations

Chapter 3 A18 Glencoe Algebra 2

Answers (Lesson 3-5)

Skill

s Pr

acti

ceS

olv

ing

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tem

s o

f E

qu

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in T

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15,

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tim

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thir

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Fin

d th

e n

um

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.9,

6,3

Cha

pter

338

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

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ATE

____

____

____

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ER

IOD

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_

3-5

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Lesson 3-5

Cha

pter

339

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-5

Copyright ©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Sol

ve e

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qual

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con

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h t

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me.

How

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aria

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s

A1-A19 A2-03-873973 5/22/06 8:25 AM Page A18

Page 19: Answers (Lesson 3-1) · A system of equations is a set of two or more equations containing the same variables. You can solve a system of linear equations by graphing the equations

Chapter 3 A19 Glencoe Algebra 2

An

swer

s

Answers (Lesson 3-5)

Wor

d Pr

oble

m P

ract

ice

So

lvin

g S

yste

ms

of

Eq

uat

ion

s in

Th

ree

Var

iab

les

Cha

pter

340

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-5

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

1.SI

BLI

NG

SA

my,

Kar

en,a

nd

Nol

an a

resi

blin

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r ag

es i

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ears

can

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repr

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by t

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vari

able

s A

,K,a

nd

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espe

ctiv

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Th

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ave

live

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tota

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22

year

s co

mbi

ned

.Kar

en h

as l

ived

twic

e as

man

y ye

ars

as A

my,

and

Nol

anh

as l

ived

6 y

ears

lon

ger

than

Am

y.U

seth

e eq

uat

ion

s A

�K

�N

�22

,K�

2A,

and

N�

A�

6 to

fin

d th

e ag

e of

eac

hsi

blin

g.A

my

is 4

,Kar

en is

8,a

nd

No

lan

is10

.

2.H

OC

KEY

Bob

by H

ull

sco

red

Ggo

als,

Aas

sist

s,an

d P

poin

ts i

n h

is N

HL

care

er.B

y de

fin

itio

n,P

�G

�A

.He

scor

ed 5

0 m

ore

goal

s th

an a

ssis

ts.H

adh

e sc

ored

15

mor

e go

als

and

15 m

ore

assi

sts,

he

wou

ld h

ave

scor

ed 1

200

poin

ts.H

ow m

any

goal

s,as

sist

s,an

dpo

ints

did

Bob

by H

ull

sco

re?

610

go

als,

560

assi

sts,

and

11

70 p

oin

ts

3.EX

ERC

ISE

Lar

ry,C

amil

le,a

nd

Sim

one

are

keep

ing

trac

k of

how

far

th

ey w

alk

each

day

.At

the

end

of t

he

wee

k,th

eyco

mbi

ned

th

eir

dist

ance

s an

d fo

un

d th

atth

ey h

ad w

alke

d 34

mil

es i

n t

otal

.Th

eyal

so l

earn

ed t

hat

Cam

ille

wal

ked

twic

eas

far

as

Lar

ry,a

nd

that

Lar

ry w

alke

d 2

mor

e m

iles

th

an S

imon

e.H

ow f

ar d

idea

ch p

erso

n w

alk?

Cam

ille

wal

ked

18

mi,

Lar

ry w

alke

d 9

mi,

and

S

imo

ne

wal

ked

7 m

i.

DIS

TAN

CES

For

Exe

rcis

es 5

an

d 6

,use

the

foll

owin

g in

form

atio

n.

Let

cbe

th

e di

stan

ce b

etw

een

Car

lisl

e an

dW

elle

sley

,let

bbe

th

e di

stan

ce b

etw

een

Car

lisl

e an

d S

ton

ebri

dge,

and

let

abe

th

edi

stan

ce b

etw

een

Wel

lesl

ey a

nd

Sto

neb

ridg

e.·I

f yo

u d

id a

cir

cuit

,tra

veli

ng

from

Car

lisl

e to

Wel

lesl

ey t

o S

ton

ebri

dge

and

back

to

Car

lisl

e,yo

u w

ould

tra

vel

73m

iles

.·S

ton

ebri

dge

is 1

2 m

iles

far

ther

th

anW

elle

sley

is

from

Car

lisl

e.·I

f yo

u d

rove

fro

m S

ton

ebri

dge

to C

arli

sle

and

back

to

Sto

neb

ridg

e,an

d th

enco

nti

nu

ed t

o W

elle

sley

th

en b

ack

toS

ton

ebri

dge,

you

wou

ld t

rave

l 10

2 m

iles

.

5.W

rite

a s

yste

m o

f li

nea

r eq

uat

ion

s to

repr

esen

t th

e si

tuat

ion

.1.

a�

b�

c�

732.

b�

c�

123.

2a�

2b�

102

6.S

olve

th

e sy

stem

of

equ

atio

ns.

Exp

lain

the

mea

nin

g of

th

e so

luti

on i

n t

he

con

text

of

the

situ

atio

n.

a�

17,b

�34

,c�

22;

It is

17

mile

s fr

om

Wel

lesl

ey t

oS

ton

ebri

dg

e,34

mile

s fr

om

Sto

neb

rid

ge

to C

arlis

le,a

nd

22

mile

s fr

om

Car

lisle

to

Wel

lesl

ey.

ab

c

Ston

ebrid

ge

Wel

lesl

ey

Carli

sle

Not d

raw

nto

sca

le

Lesson 3-5

Cha

pter

341

Gle

ncoe

Alg

ebra

2

NA

ME

____

____

____

____

____

____

____

____

____

____

____

__D

ATE

____

____

____

__P

ER

IOD

____

_

3-5

Copyright ©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Enri

chm

ent

Ho

mo

gen

ou

s S

yste

ms

A s

yste

m o

f eq

uat

ion

s is

cal

led

hom

ogen

eou

s if

it

is o

f th

e fo

rm:

gz�

hy

�kz

�0

dx

�ey

�fz

�0

ax�

by�

cz�

0

Hom

ogen

eou

s sy

stem

s h

ave

som

e u

niq

ue

char

acte

rist

ics

that

set

th

em a

part

fro

m g

ener

alsy

stem

s of

equ

atio

ns.

Th

e fo

llow

ing

exer

cise

s w

ill

expl

ore

som

e of

th

ese

un

iqu

ech

arac

teri

stic

s.

1.E

valu

ate

the

foll

owin

g st

atem

ent.

Is t

his

sta

tem

ent

alw

ays,

som

etim

es,o

r n

ever

tru

e?E

xpal

in y

our

reas

onin

g.E

very

hom

ogen

eou

s sy

stem

of

equ

atio

ns

wil

l h

ave

at l

east

on

e tr

ivia

l so

luti

on:(

0,0,

0).

Alw

ays;

Sam

ple

an

swer

:if

yo

u r

epla

ce e

ach

var

iab

le w

ith

0,y

ou

will

alw

ays

get

eac

h e

qu

atio

n e

qu

al t

o 0

.

2.F

ind

a n

on-t

rivi

al s

olu

tion

to

the

foll

owin

g h

omog

enou

s sy

stem

of

equ

atio

ns.

x�

y�

5z�

02x

�y

�7z

�0

x�

2z�

0

x�

�2z

and

y�

�3z

;C

ho

ose

a n

um

ber

fo

r z,

for

exam

ple

,z�

1.S

o,a

sam

ple

an

swer

is (

�2,

�3,

1).

3.M

ult

iply

th

e so

luti

on y

ou f

oun

d in

Exe

rcis

e 2

by 3

.Is

the

new

ord

ered

tri

ple

a so

luti

on t

oth

e sy

stem

?ye

s

4.M

ult

iply

th

e so

luti

on y

ou f

oun

d in

Exe

rcis

e 2

by �

6.Is

th

e n

ew o

rder

ed t

ripl

e a

solu

tion

to t

he

syst

em?

yes

5.M

ake

a co

nje

ctu

re a

bou

t an

y m

ult

iple

of

a gi

ven

sol

uti

on t

o a

hom

ogen

eou

s sy

stem

of

equ

atio

ns.

Sam

ple

an

swer

:an

y m

ult

iple

of

a g

iven

so

luti

on

to

a h

om

og

eneo

us

syst

em o

f eq

uat

ion

s w

ill a

lso

be

a so

luti

on

.

6.M

ake

a co

nje

ctu

re a

bou

t th

e n

um

ber

of s

olu

tion

s th

at a

hom

ogen

eou

s sy

stem

of

equ

atio

ns

wil

l h

ave

if i

t h

as a

t le

ast

one

non

-tri

vial

sol

uti

on.

Sam

ple

an

swer

:it

will

hav

e an

infi

nit

e n

um

ber

of

solu

tio

ns.

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