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5 x y = 4 x + 6 y = 2 and ( 4 , 0 )

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−3 x 5 y = 13   x + 4 y = 10 and ( −6 , 1 )

Yes

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3 x + 7 y = 1 2 x + 4 y = 0 and ( 2 , 3 )

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−2 x + 5 y = 7    2 x + 9 y = 7 and ( −1 , 1 )

Yes

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x + 8 y = 43 3 x −2 y = −1 and ( 3 , 5 )

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For the following exercises, solve each system by substitution.

   x + 3 y = 5 2 x + 3 y = 4

( −1 , 2 )

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  3 x −2 y = 18 5 x + 10 y = −10

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4 x + 2 y = −10 3 x + 9 y = 0

( −3 , 1 )

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2 x + 4 y = −3.8 9 x −5 y = 1.3

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2 x + 3 y = 1.2 3 x 6 y = 1.8

( 3 5 , 0 )

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    x −0.2 y = 1 −10 x + 2 y = 5

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     3 x + 5 y = 9 30 x + 50 y = −90

No solutions exist.

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  −3 x + y = 2 12 x −4 y = −8

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1 2 x + 1 3 y = 16 1 6 x + 1 4 y = 9

( 72 5 , 132 5 )

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1 4 x + 3 2 y = 11 1 8 x + 1 3 y = 3

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For the following exercises, solve each system by addition.

−2 x + 5 y = −42    7 x + 2 y = 30

( 6 , −6 )

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6 x −5 y = −34 2 x + 6 y = 4

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     5 x y = −2.6 −4 x −6 y = 1.4

( 1 2 , 1 10 )

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7 x −2 y = 3 4 x + 5 y = 3.25

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  −x + 2 y = −1 5 x −10 y = 6

No solutions exist.

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       7 x + 6 y = 2 −28 x −24 y = −8

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5 6 x + 1 4 y = 0 1 8 x 1 2 y = 43 120

( 1 5 , 2 3 )

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   1 3 x + 1 9 y = 2 9 1 2 x + 4 5 y = 1 3

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−0.2 x + 0.4 y = 0.6             x −2 y = −3

( x , x + 3 2 )

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−0.1 x + 0.2 y = 0.6       5 x −10 y = 1

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For the following exercises, solve each system by any method.

5 x + 9 y = 16    x + 2 y = 4

( −4 , 4 )

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6 x −8 y = −0.6 3 x + 2 y = 0.9

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5 x −2 y = 2.25 7 x −4 y = 3

( 1 2 , 1 8 )

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   x 5 12 y = 55 12 −6 x + 5 2 y = 55 2

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7 x −4 y = 7 6 2 x + 4 y = 1 3

( 1 6 , 0 )

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3 x + 6 y = 11 2 x + 4 y = 9

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       7 3 x 1 6 y = 2 21 6 x + 3 12 y = −3

( x , 2 ( 7 x −6 ) )

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1 2 x + 1 3 y = 1 3 3 2 x + 1 4 y = 1 8

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2.2 x + 1.3 y = −0.1 4.2 x + 4.2 y = 2.1

( 5 6 , 4 3 )

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  0.1 x + 0.2 y = 2 0.35 x −0.3 y = 0

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Graphical

For the following exercises, graph the system of equations and state whether the system is consistent, inconsistent, or dependent and whether the system has one solution, no solution, or infinite solutions.

3 x y = 0.6 x −2 y = 1.3

Consistent with one solution

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x + 2 y = 4   2 x −4 y = 1

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   x + 2 y = 7 2 x + 6 y = 12

Consistent with one solution

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3 x −5 y = 7    x −2 y = 3

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   3 x −2 y = 5 −9 x + 6 y = −15

Dependent with infinitely many solutions

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Technology

For the following exercises, use the intersect function on a graphing device to solve each system. Round all answers to the nearest hundredth.

    0.1 x + 0.2 y = 0.3 −0.3 x + 0.5 y = 1

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−0.01 x + 0.12 y = 0.62 0.15 x + 0.20 y = 0.52

( −3.08 , 4.91 )

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0.5 x + 0.3 y = 4 0.25 x −0.9 y = 0.46

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0.15 x + 0.27 y = 0.39 −0.34 x + 0.56 y = 1.8

( −1.52 , 2.29 )

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−0.71 x + 0.92 y = 0.13 0.83 x + 0.05 y = 2.1

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Extensions

For the following exercises, solve each system in terms of A , B , C , D , E , and F where A F are nonzero numbers. Note that A B and A E B D .

x + y = A x y = B

( A + B 2 , A B 2 )

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A x + y = 0 B x + y = 1

( −1 A B , A A B )

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A x + B y = C D x + E y = F

( C E B F B D A E , A F C D B D A E )

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Real-world applications

For the following exercises, solve for the desired quantity.

A stuffed animal business has a total cost of production C = 12 x + 30 and a revenue function R = 20 x . Find the break-even point.

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A fast-food restaurant has a cost of production C ( x ) = 11 x + 120 and a revenue function R ( x ) = 5 x . When does the company start to turn a profit?

They never turn a profit.

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A cell phone factory has a cost of production C ( x ) = 150 x + 10 , 000 and a revenue function R ( x ) = 200 x . What is the break-even point?

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A musician charges C ( x ) = 64 x + 20,000 , where x is the total number of attendees at the concert. The venue charges $80 per ticket. After how many people buy tickets does the venue break even, and what is the value of the total tickets sold at that point?

( 1 , 250 , 100 , 000 )

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A guitar factory has a cost of production C ( x ) = 75 x + 50,000. If the company needs to break even after 150 units sold, at what price should they sell each guitar? Round up to the nearest dollar, and write the revenue function.

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Questions & Answers

calculate molarity of NaOH solution when 25.0ml of NaOH titrated with 27.2ml of 0.2m H2SO4
Gasin Reply
what's Thermochemistry
rhoda Reply
the study of the heat energy which is associated with chemical reactions
Kaddija
How was CH4 and o2 was able to produce (Co2)and (H2o
Edafe Reply
explain please
Victory
First twenty elements with their valences
Martine Reply
what is chemistry
asue Reply
what is atom
asue
what is the best way to define periodic table for jamb
Damilola Reply
what is the change of matter from one state to another
Elijah Reply
what is isolation of organic compounds
IKyernum Reply
what is atomic radius
ThankGod Reply
Read Chapter 6, section 5
Dr
Read Chapter 6, section 5
Kareem
Atomic radius is the radius of the atom and is also called the orbital radius
Kareem
atomic radius is the distance between the nucleus of an atom and its valence shell
Amos
Read Chapter 6, section 5
paulino
Bohr's model of the theory atom
Ayom Reply
is there a question?
Dr
when a gas is compressed why it becomes hot?
ATOMIC
It has no oxygen then
Goldyei
read the chapter on thermochemistry...the sections on "PV" work and the First Law of Thermodynamics should help..
Dr
Which element react with water
Mukthar Reply
Mgo
Ibeh
an increase in the pressure of a gas results in the decrease of its
Valentina Reply
definition of the periodic table
Cosmos Reply
What is the lkenes
Da Reply
what were atoms composed of?
Moses Reply
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Source:  OpenStax, Precalculus. OpenStax CNX. Jan 19, 2016 Download for free at https://legacy.cnx.org/content/col11667/1.6
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