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Solve: 2 u ( 5 u 1 ) = 0 .

u = 0 , u = 1 5

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Solve: w ( 2 w + 3 ) = 0 .

w = 0 , w = 3 2

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It may appear that there is only one factor in the next example. Remember, however, that ( y 8 ) 2 means ( y 8 ) ( y 8 ) .

Solve: ( y 8 ) 2 = 0 .

Solution

This image shows the steps for solving the equation (y – 8) squared = 0. The first step is to write the left hand side as a product, (y – 8)(y – 8) = 0. The next step is using the zero product property and set each factor equal to 0, y – 8 = 0 and y – 8 -= 0. Solve both equations, y = 8 and y = 8. When the solution repeats, it is a double root. Finally, check the solution by substituting back into the original equation.
( y 8 ) 2 = 0
Rewrite the left side as a product. ( y 8 ) ( y 8 ) = 0
Use the Zero Product Property and
set each factor to 0.
y 8 = 0 y 8 = 0
Solve the equations. y = 8 y = 8
When a solution repeats, we call it
a double root.
Check your answer.
.

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Solve: ( x + 1 ) 2 = 0 .

x = 1

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Solve: ( v 2 ) 2 = 0 .

v = 2

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Solve quadratic equations by factoring

Each of the equations we have solved in this section so far had one side in factored form. In order to use the Zero Product Property, the quadratic equation must be factored, with zero on one side. So we be sure to start with the quadratic equation in standard form, a x 2 + b x + c = 0 . Then we factor the expression on the left.

How to solve a quadratic equation by factoring

Solve: x 2 + 2 x 8 = 0 .

Solution

This table gives the steps for solving the equation x squared + 2 x – 8 = 0. The first step is writing the equation in standard quadratic form, which it is. The second step is factoring the quadratic expression x squared + 2 x – 8. The factors are (x + 4), (x – 2). The next step is using the zero product property and set each factor equal to 0, x + 4 = 0 and x – 2 = 0. The next step is solving both linear equations, x = −4 or x = 2. The last step is checking both solutions by substituting them into the original equation.
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Solve: x 2 x 12 = 0 .

x = 4 , x = −3

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Solve: b 2 + 9 b + 14 = 0 .

b = −2 , b = −7

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Solve a quadratic equation by factoring.

  1. Write the quadratic equation in standard form, a x 2 + b x + c = 0 .
  2. Factor the quadratic expression.
  3. Use the Zero Product Property.
  4. Solve the linear equations.
  5. Check.

Before we factor, we must make sure the quadratic equation is in standard form.

Solve: 2 y 2 = 13 y + 45 .

Solution

This image shows the steps for solving the equation 2 y squared = 13 y + 45. The first step is writing the equation in standard quadratic form, 2 y squared – 13 y – 45 = 0. The second step is to factor the quadratic expression, (2 y + 5)(y – 9) = 0. The third step is to use the zero product property to set each factor equal to 0, 2 y + 5 = 0 or y – 9 = 0. Solve each equation, y = −5/2 or y = 9. Finally, check the answers by substituting them back into the original equation.
2 y 2 = 13 y + 45
Write the quadratic equation in standard form. 2 y 2 13 y 45 = 0
Factor the quadratic expression. ( 2 y + 5 ) ( y 9 ) = 0
Use the Zero Product Property
to set each factor to 0.
2 y + 5 = 0 y 9 = 0
Solve each equation. y = 5 2 y = 9
Check your answers.
.

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Solve: 3 c 2 = 10 c 8 .

c = 0 , c = 4 3

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Solve: 2 d 2 5 d = 3 .

d = 3 , d = 1 2

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Solve: 5 x 2 13 x = 7 x .

Solution

This image shows the steps for solving the equation 5 x squared – 13 x = 7 x. The first step is writing the equation in standard quadratic form, 5 x squared – 20 x = 0. The second step is to factor the quadratic expression, 5 x(x – 4)= 0. The third step is to use the zero product property to set each factor equal to 0, 5 x = 0 or x − 4 = 0. Solve each equation, x = 0 or x = 4. Finally, check the answers by substituting them back into the original equation.
5 x 2 13 x = 7 x
Write the quadratic equation in standard form. 5 x 2 20 x = 0
Factor the left side of the equation. 5 x ( x 4 ) = 0
Use the Zero Product Property
to set each factor to 0.
5 x = 0 x 4 = 0
Solve each equation. x = 0 x = 4
Check your answers.
.

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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
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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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