Transcript
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

y

Ox

y

Ox

y

O2

2

x

y

Ox

y

Ox

y

O

x

y

Ox

y

Ox

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

luti

on.A

sol

uti

on i

s an

ord

ered

tri

ple

.

Sol

ve t

his

sys

tem

of

equ

atio

ns.

3x�

y�

z�

�6

2x�

y�

2z�

84x

�y

�3z

��

21

Ste

p 1

Use

eli

min

atio

n t

o m

ake

a sy

stem

of

two

equ

atio

ns

in t

wo

vari

able

s.3x

�y

�z

��

6F

irst

equa

tion

2x�

y�

2z�

8S

econ

d eq

uatio

n

(�)

2x�

y�

2z�

8S

econ

d eq

uatio

n(�

) 4x

�y

�3z

��

21T

hird

equ

atio

n

5x�

z�

2A

dd t

o el

imin

ate

y.6x

z�

�13

Add

to

elim

inat

e y.

Ste

p 2

Sol

ve t

he

syst

em o

f tw

o eq

uat

ion

s.5x

�z

�2

(�)

6x�

z�

�13

11x

��

11A

dd t

o el

imin

ate

z.

x�

�1

Div

ide

both

sid

es b

y 11

.

Su

bsti

tute

�1

for

xin

on

e of

th

e eq

uat

ion

s w

ith

tw

o va

riab

les

and

solv

e fo

r z.

5x�

z�

2E

quat

ion

with

tw

o va

riabl

es

5(�

1) �

z�

2R

epla

ce x

with

�1.

�5

�z

�2

Mul

tiply

.

z�

7A

dd 5

to

both

sid

es.

Th

e re

sult

so

far

is x

��

1 an

d z

�7.

Ste

p 3

Su

bsti

tute

�1

for

xan

d 7

for

zin

on

e of

th

e or

igin

al e

quat

ion

s w

ith

th

ree

vari

able

s.3x

�y

�z

��

6O

rigin

al e

quat

ion

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s

Exam

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Lesson 3-5

Cha

pter

337

Gle

ncoe

Alg

ebra

2

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ME

____

____

____

____

____

____

____

____

____

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____

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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.

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

$99

on M

ond

ay.O

n T

ues

day

th

ey s

old

4 b

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ases

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$78

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nes

day

th

ey s

old

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ase

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hat

are

th

e p

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st d

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e th

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e

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1.FI

TNES

S TR

AIN

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Car

ly i

s tr

ain

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her

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mes

as

far

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he

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d sh

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ain

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TERT

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t th

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n s

pen

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ara

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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

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tem

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f E

qu

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15,

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Fin

d th

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um

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.9,

6,3

Cha

pter

338

Gle

ncoe

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ebra

2

NA

ME

____

____

____

____

____

____

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____

____

____

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ATE

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____

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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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POR

TSA

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ia H

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7 po

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ix p

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ts a

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arde

d fo

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ch t

ouch

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n.A

fter

eac

h t

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ne

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r th

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tra

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-poi

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me.

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gam

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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

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an a

resi

blin

gs.T

hei

r ag

es i

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ears

can

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repr

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vari

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s A

,K,a

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espe

ctiv

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22

year

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mbi

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as l

ived

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e as

man

y ye

ars

as A

my,

and

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6 y

ears

lon

ger

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seth

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�K

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my

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,Kar

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2.H

OC

KEY

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ull

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HL

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ld h

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200

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ow m

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re?

610

go

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560

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11

70 p

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3.EX

ERC

ISE

Lar

ry,C

amil

le,a

nd

Sim

one

are

keep

ing

trac

k of

how

far

th

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alk

each

day

.At

the

end

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wee

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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

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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

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n w

alk?

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ille

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18

mi,

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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.

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


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