<< Chapter < Page Chapter >> Page >

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

Got questions? Get instant answers now!

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

Yes

Got questions? Get instant answers now!

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

Got questions? Get instant answers now!

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

Yes

Got questions? Get instant answers now!

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

Got questions? Get instant answers now!

For the following exercises, solve each system by substitution.

   x + 3 y = 5 2 x + 3 y = 4

( −1 , 2 )

Got questions? Get instant answers now!

  3 x −2 y = 18 5 x + 10 y = −10

Got questions? Get instant answers now!

4 x + 2 y = −10 3 x + 9 y = 0

( −3 , 1 )

Got questions? Get instant answers now!

2 x + 4 y = −3.8 9 x −5 y = 1.3

Got questions? Get instant answers now!

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

( 3 5 , 0 )

Got questions? Get instant answers now!

    x −0.2 y = 1 −10 x + 2 y = 5

Got questions? Get instant answers now!

     3 x + 5 y = 9 30 x + 50 y = −90

No solutions exist.

Got questions? Get instant answers now!

  −3 x + y = 2 12 x −4 y = −8

Got questions? Get instant answers now!

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

( 72 5 , 132 5 )

Got questions? Get instant answers now!

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

Got questions? Get instant answers now!

For the following exercises, solve each system by addition.

−2 x + 5 y = −42    7 x + 2 y = 30

( 6 , −6 )

Got questions? Get instant answers now!

6 x −5 y = −34 2 x + 6 y = 4

Got questions? Get instant answers now!

     5 x y = −2.6 −4 x −6 y = 1.4

( 1 2 , 1 10 )

Got questions? Get instant answers now!

7 x −2 y = 3 4 x + 5 y = 3.25

Got questions? Get instant answers now!

  −x + 2 y = −1 5 x −10 y = 6

No solutions exist.

Got questions? Get instant answers now!

       7 x + 6 y = 2 −28 x −24 y = −8

Got questions? Get instant answers now!

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

( 1 5 , 2 3 )

Got questions? Get instant answers now!

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

Got questions? Get instant answers now!

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

( x , x + 3 2 )

Got questions? Get instant answers now!

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

Got questions? Get instant answers now!

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

5 x + 9 y = 16    x + 2 y = 4

( −4 , 4 )

Got questions? Get instant answers now!

6 x −8 y = −0.6 3 x + 2 y = 0.9

Got questions? Get instant answers now!

5 x −2 y = 2.25 7 x −4 y = 3

( 1 2 , 1 8 )

Got questions? Get instant answers now!

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

Got questions? Get instant answers now!

7 x −4 y = 7 6 2 x + 4 y = 1 3

( 1 6 , 0 )

Got questions? Get instant answers now!

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

Got questions? Get instant answers now!

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

( x , 2 ( 7 x −6 ) )

Got questions? Get instant answers now!

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

Got questions? Get instant answers now!

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

( 5 6 , 4 3 )

Got questions? Get instant answers now!

  0.1 x + 0.2 y = 2 0.35 x −0.3 y = 0

Got questions? Get instant answers now!

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

Got questions? Get instant answers now!

x + 2 y = 4   2 x −4 y = 1

Got questions? Get instant answers now!

   x + 2 y = 7 2 x + 6 y = 12

Consistent with one solution

Got questions? Get instant answers now!

3 x −5 y = 7    x −2 y = 3

Got questions? Get instant answers now!

   3 x −2 y = 5 −9 x + 6 y = −15

Dependent with infinitely many solutions

Got questions? Get instant answers now!

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

Got questions? Get instant answers now!

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

( −3.08 , 4.91 )

Got questions? Get instant answers now!

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

Got questions? Get instant answers now!

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

( −1.52 , 2.29 )

Got questions? Get instant answers now!

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

Got questions? Get instant answers now!

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 )

Got questions? Get instant answers now!

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

( −1 A B , A A B )

Got questions? Get instant answers now!

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 )

Got questions? Get instant answers now!

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.

Got questions? Get instant answers now!

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.

Got questions? Get instant answers now!

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?

Got questions? Get instant answers now!

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 )

Got questions? Get instant answers now!

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.

Got questions? Get instant answers now!

Questions & Answers

Ayele, K., 2003. Introductory Economics, 3rd ed., Addis Ababa.
Widad Reply
can you send the book attached ?
Ariel
?
Ariel
What is economics
Widad Reply
the study of how humans make choices under conditions of scarcity
AI-Robot
U(x,y) = (x×y)1/2 find mu of x for y
Desalegn Reply
U(x,y) = (x×y)1/2 find mu of x for y
Desalegn
what is ecnomics
Jan Reply
this is the study of how the society manages it's scarce resources
Belonwu
what is macroeconomic
John Reply
macroeconomic is the branch of economics which studies actions, scale, activities and behaviour of the aggregate economy as a whole.
husaini
etc
husaini
difference between firm and industry
husaini Reply
what's the difference between a firm and an industry
Abdul
firm is the unit which transform inputs to output where as industry contain combination of firms with similar production 😅😅
Abdulraufu
Suppose the demand function that a firm faces shifted from Qd  120 3P to Qd  90  3P and the supply function has shifted from QS  20  2P to QS 10  2P . a) Find the effect of this change on price and quantity. b) Which of the changes in demand and supply is higher?
Toofiq Reply
explain standard reason why economic is a science
innocent Reply
factors influencing supply
Petrus Reply
what is economic.
Milan Reply
scares means__________________ends resources. unlimited
Jan
economics is a science that studies human behaviour as a relationship b/w ends and scares means which have alternative uses
Jan
calculate the profit maximizing for demand and supply
Zarshad Reply
Why qualify 28 supplies
Milan
what are explicit costs
Nomsa Reply
out-of-pocket costs for a firm, for example, payments for wages and salaries, rent, or materials
AI-Robot
concepts of supply in microeconomics
David Reply
economic overview notes
Amahle Reply
identify a demand and a supply curve
Salome Reply
i don't know
Parul
there's a difference
Aryan
Demand curve shows that how supply and others conditions affect on demand of a particular thing and what percent demand increase whith increase of supply of goods
Israr
Hi Sir please how do u calculate Cross elastic demand and income elastic demand?
Abari
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Precalculus. OpenStax CNX. Jan 19, 2016 Download for free at https://legacy.cnx.org/content/col11667/1.6
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Precalculus' conversation and receive update notifications?

Ask