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Solve a System of Linear Equations by Graphing

In the following exercises, solve the following systems of equations by graphing.

{ 3 x + y = 6 x + 3 y = −6

( 3 , −3 )
This figure shows a graph on an x y-coordinate plane of 3x plus y = 6 and x plus 3y = negative 6.

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{ y = x 2 y = −2 x 2

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{ 2 x y = 6 y = 4

( 5 , 4 )
This figure shows a graph on an x y-coordinate plane of 2x – y = 6 and y = 4.

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{ 2 x y = 5 4 x 2 y = 10

coincident lines
This figure shows a graph on an x y-coordinate plane of 2x – y = 5 and 4x – 2y = 10.

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

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Determine the Number of Solutions of a Linear System

In the following exercises, without graphing determine the number of solutions and then classify the system of equations.

{ y = 2 5 x + 2 −2 x + 5 y = 10

infinitely many solutions, consistent system, dependent equations

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{ 3 x + 2 y = 6 y = −3 x + 4

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{ 5 x 4 y = 0 y = 5 4 x 5

no solutions, inconsistent system, independent equations

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{ y = 3 4 x + 1 6 x + 8 y = 8

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Solve Applications of Systems of Equations by Graphing

LaVelle is making a pitcher of caffe mocha. For each ounce of chocolate syrup, she uses five ounces of coffee. How many ounces of chocolate syrup and how many ounces of coffee does she need to make 48 ounces of caffe mocha?

LaVelle needs 8 ounces of chocolate syrup and 40 ounces of coffee.

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Eli is making a party mix that contains pretzels and chex. For each cup of pretzels, he uses three cups of chex. How many cups of pretzels and how many cups of chex does he need to make 12 cups of party mix?

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Section 5.2 Solve Systems of Equations by Substitution

Solve a System of Equations by Substitution

In the following exercises, solve the systems of equations by substitution.

{ 3 x y = −5 y = 2 x + 4

( −1 , 2 )

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{ 3 x 2 y = 2 y = 1 2 x + 3

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{ x y = 0 2 x + 5 y = −14

( −2 , −2 )

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{ y = −2 x + 7 y = 2 3 x 1

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{ y = −5 x 5 x + y = 6

no solution

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{ y = 1 3 x + 2 x + 3 y = 6

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Solve Applications of Systems of Equations by Substitution

In the following exercises, translate to a system of equations and solve.

The sum of two number is 55. One number is 11 less than the other. Find the numbers.

The numbers are 22 and 33.

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The perimeter of a rectangle is 128. The length is 16 more than the width. Find the length and width.

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The measure of one of the small angles of a right triangle is 2 less than 3 times the measure of the other small angle. Find the measure of both angles.

The measures are 23 degrees and 67 degrees.

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Gabriela works for an insurance company that pays her a salary of $32,000 plus a commission of $100 for each policy she sells. She is considering changing jobs to a company that would pay a salary of $40,000 plus a commission of $80 for each policy sold. How many policies would Gabriela need to sell to make the total pay the same?

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Section 5.3 Solve Systems of Equations by Elimination

Solve a System of Equations by Elimination In the following exercises, solve the systems of equations by elimination.

{ x + y = 12 x y = −10

( 1 , 11 )

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{ 4 x + 2 y = 2 −4 x 3 y = −9

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{ 3 x 8 y = 20 x + 3 y = 1

( 4 , −1 )

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{ 3 x 2 y = 6 4 x + 3 y = 8

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

( −2 , 5 )

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{ x + 3 y = 8 2 x 6 y = −20

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Solve Applications of Systems of Equations by Elimination

In the following exercises, translate to a system of equations and solve.

The sum of two numbers is −90 . Their difference is 16 . Find the numbers.

The numbers are −37 and −53 .

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Omar stops at a donut shop every day on his way to work. Last week he had 8 donuts and 5 cappuccinos, which gave him a total of 3,000 calories. This week he had 6 donuts and 3 cappuccinos, which was a total of 2,160 calories. How many calories are in one donut? How many calories are in one cappuccino?

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Questions & Answers

A golfer on a fairway is 70 m away from the green, which sits below the level of the fairway by 20 m. If the golfer hits the ball at an angle of 40° with an initial speed of 20 m/s, how close to the green does she come?
Aislinn Reply
cm
tijani
what is titration
John Reply
what is physics
Siyaka Reply
A mouse of mass 200 g falls 100 m down a vertical mine shaft and lands at the bottom with a speed of 8.0 m/s. During its fall, how much work is done on the mouse by air resistance
Jude Reply
Can you compute that for me. Ty
Jude
what is the dimension formula of energy?
David Reply
what is viscosity?
David
what is inorganic
emma Reply
what is chemistry
Youesf Reply
what is inorganic
emma
Chemistry is a branch of science that deals with the study of matter,it composition,it structure and the changes it undergoes
Adjei
please, I'm a physics student and I need help in physics
Adjanou
chemistry could also be understood like the sexual attraction/repulsion of the male and female elements. the reaction varies depending on the energy differences of each given gender. + masculine -female.
Pedro
A ball is thrown straight up.it passes a 2.0m high window 7.50 m off the ground on it path up and takes 1.30 s to go past the window.what was the ball initial velocity
Krampah Reply
2. A sled plus passenger with total mass 50 kg is pulled 20 m across the snow (0.20) at constant velocity by a force directed 25° above the horizontal. Calculate (a) the work of the applied force, (b) the work of friction, and (c) the total work.
Sahid Reply
you have been hired as an espert witness in a court case involving an automobile accident. the accident involved car A of mass 1500kg which crashed into stationary car B of mass 1100kg. the driver of car A applied his brakes 15 m before he skidded and crashed into car B. after the collision, car A s
Samuel Reply
can someone explain to me, an ignorant high school student, why the trend of the graph doesn't follow the fact that the higher frequency a sound wave is, the more power it is, hence, making me think the phons output would follow this general trend?
Joseph Reply
Nevermind i just realied that the graph is the phons output for a person with normal hearing and not just the phons output of the sound waves power, I should read the entire thing next time
Joseph
Follow up question, does anyone know where I can find a graph that accuretly depicts the actual relative "power" output of sound over its frequency instead of just humans hearing
Joseph
"Generation of electrical energy from sound energy | IEEE Conference Publication | IEEE Xplore" ***ieeexplore.ieee.org/document/7150687?reload=true
Ryan
what's motion
Maurice Reply
what are the types of wave
Maurice
answer
Magreth
progressive wave
Magreth
hello friend how are you
Muhammad Reply
fine, how about you?
Mohammed
hi
Mujahid
A string is 3.00 m long with a mass of 5.00 g. The string is held taut with a tension of 500.00 N applied to the string. A pulse is sent down the string. How long does it take the pulse to travel the 3.00 m of the string?
yasuo Reply
Who can show me the full solution in this problem?
Reofrir Reply
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Source:  OpenStax, Elementary algebra. OpenStax CNX. Jan 18, 2017 Download for free at http://cnx.org/content/col12116/1.2
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