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Sample set b

Factor 24 x 2 41 x + 12 .

Factor the first and last terms.

24 x 2 12
24 x , x 12 , 1
12 x , 2 x 6 , 2
8 x , 3 x 4 , 3
6 x , 4 x

Rather than starting with the 24 x , x and 12 , 1 , pick some intermediate values, 8 x and 3 x , the 6 x and 4 x , or the 6 and 2 , or the 4 and 3 .

24 x 2 41 x + 12 = ( 8 x 3 ) ( 3 x 4 )

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Practice set b

Factor 48 x 2 + 22 x - 15 .

( 6 x + 5 ) ( 8 x 3 )

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Factor 54 y 2 + 39 y w 28 w 2 .

( 9 y 4 w ) ( 6 y + 7 w )

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The collect and discard method of factoring a x 2 + b x + c

Collect and discard method

Consider the polynomial 6 x 2 + x 12 . We begin by identifying a and c . In this case, a = 6 and c = 12 . We start out as we would with a = 1 .

6 x 2 + x 12 : ( 6 x ) ( 6 x )

Now, compute a c .

a c = ( 6 ) ( 12 ) = 72

Find the factors of 72 that add to 1, the coefficient of x , the linear term. The factors are 9 and 8 . Include these factors in the parentheses.

6 x 2 + x 12 : ( 6 x + 9 ) ( 6 x 8 )

But we have included too much. We must eliminate the surplus. Factor each parentheses.

6 x 2 + x 12 : 3 ( 2 x + 3 ) 2 ( 3 x 4 )

Discard the factors that multiply to a = 6 . In this case, 3 and 2. We are left with the proper factorization.

6 x 2 + x 12 = ( 2 x + 3 ) ( 3 x 4 )

Sample set c

Factor 10 x 2 + 23 x 5 .

Identify a = 10 and b = 5 .

10 x 2 + 23 x 5 ; ( 10 x ) ( 10 x )

Compute

a c = ( 10 ) ( 5 ) = 50

Find the factors of 50 that add to + 23 , the coefficient of x , the linear term. The factors are 25 and 2 . Place these numbers into the parentheses.

10 x 2 + 23 x 5 : ( 10 x + 25 ) ( 10 x 2 )

We have collected too much. Factor each set of parentheses and eliminate the surplus.

10 x 2 + 23 x 5 : ( 5 ) ( 2 x + 5 ) ( 2 ) ( 5 x 1 )

Discard the factors that multiply to a = 10 . In this case, 5 and 2.

10 x 2 + 23 x 5 = ( 2 x + 5 ) ( 5 x 1 )

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Factor 8 x 2 30 x 27 .

Identify a = 8 and c = 27 .

8 x 2 30 x 27 : ( 8 x ) ( 8 x )

Compute

a c = ( 8 ) ( 27 ) = 216

Find the factors of 216 that add to 30 , the coefficient of x , the linear term. This requires some thought. The factors are 36 and 6. Place these numbers into the parentheses.

8 x 2 30 x 27 : ( 8 x 36 ) ( 8 x + 6 )

We have collected too much. Factor each set of parentheses and eliminate the surplus.

8 x 2 30 x 27 : ( 4 ) ( 2 x 9 ) ( 2 ) ( 4 x + 3 )

Discard the factors that multiply to a = 8 . In this case, 4 and 2.

8 x 2 30 x 27 = ( 2 x 9 ) ( 4 x + 3 )

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Factor 18 x 2 5 x y 2 y 2 .

Identify a = 18 and c = 2 .

18 x 2 5 x y 2 y 2 : ( 18 x ) ( 18 x )

Compute

a c = ( 18 ) ( 2 ) = 36

Find the factors of 36 that add to 5 , the coefficient of x y . In this case, 9 and 4. Place these numbers into the parentheses, affixing y to each.

18 x 2 5 x y 2 y 2 : ( 18 x 9 y ) ( 18 x + 4 y )

We have collected too much. Factor each set of parentheses and eliminate the surplus.

18 x 2 5 x y 2 y 2 : ( 9 ) ( 2 x y ) ( 2 ) ( 9 x + 2 y )

Discard the factors that multiply to a = 18 . In this case, 9 and 4.

18 x 2 5 x y 2 y 2 = ( 2 x y ) ( 9 x + 2 y )

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Practice set c

Factor 6 x 2 + 7 x 3 .

( 3 x 1 ) ( 2 x + 3 )

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Factor 14 x 2 31 x 10 .

( 7 x + 2 ) ( 2 x 5 )

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Factor 48 x 2 + 22 x 15 .

( 6 x + 5 ) ( 8 x 3 )

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Factor 10 x 2 23 x w + 12 w 2 .

( 5 x 4 w ) ( 2 x 3 w )

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Exercises

Factor the following problems, if possible.

x 2 + 3 x + 2

( x + 2 ) ( x + 1 )

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2 x 2 + 7 x + 5

( 2 x + 5 ) ( x + 1 )

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2 x 2 + 11 x + 12

( 2 x + 3 ) ( x + 4 )

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3 x 2 x 4

( 3 x 4 ) ( x + 1 )

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4 x 2 + 8 x 21

( 2 x 3 ) ( 2 x + 7 )

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9 a 2 7 a + 2

not factorable

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16 y 2 - 26 y + 3

( 8 y 1 ) ( 2 y 3 )

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10 x 2 + 29 x + 10

( 5 x + 2 ) ( 2 x + 5 )

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81 a 2 + 19 a + 2

not factorable

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24 x 2 34 x + 5

( 6 x 1 ) ( 4 x 5 )

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24 x 2 + 26 x 5

( 6 x 1 ) ( 4 x + 5 )

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6 x 2 + 5 x y + y 2

( 3 x + y ) ( 2 x + y )

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For the following problems, the given trinomial occurs when solving the corresponding applied problem. Factor each trinomial. You do not need to solve the problem.

5 r 2 24 r 5 .

It takes 5 hours to paddle a boat 12 miles downstream and then back. The current flows at the rate of 1 mile per hour. At what rate was the boat paddled?

( 5 r + 1 ) ( r 5 )

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x 2 + 5 x 84 .

The length of a rectangle is 5 inches more than the width of the rectangle. If the area of the rectangle is 84 square inches, what are the length and width of the rectangle?

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x 2 + 24 x 145 .

A square measures 12 inches on each side. Another square is to be drawn around this square in such a way that the total area is 289 square inches. What is the distance from the edge of the smaller square to the edge of the larger square? (The two squares have the same center.)

( x + 29 ) ( x 5 )

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x 2 + 8 x 20 .

A woman wishes to construct a rectangular box that is open at the top. She wishes it to be 4 inches high and have a rectangular base whose length is three times the width. The material used for the base costs $2 per square inch, and the material used for the sides costs $1.50 per square inch. The woman will spend exactly $120 for materials. Find the dimension of the box (length of the base, width of the base, and height).

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For the following problems, factor the trinomials if possible.

16 x 2 8 x y 3 y 2

( 4 x + y ) ( 4 x 3 y )

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12 a 2 + 7 a b + 12 b 2

not factorable

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8 a 2 + 10 a b 6 b 2

2 ( 4 a 2 + 5 a b 3 b 2 )

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12 b 4 + 30 b 2 a + 12 a 2

6 ( 2 b 2 + a ) ( b 2 + 2 a )

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30 a 4 b 4 3 a 2 b 2 6 c 2

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3 a 6 3 a 3 b 2 18 b 4

3 ( a 3 + 2 b 2 ) ( a 3 3 b 2 )

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20 a 2 b 2 + 2 a b c 2 6 a 2 c 4

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14 a 2 z 2 40 a 3 z 2 46 a 4 z 2

2 a 2 z 2 ( 7 20 a 23 a 2 )  or  2 a 2 z 2 ( 23 a 2 + 20 a 7 )

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Exercises for review

( [link] ) Simplify ( a 3 b 6 ) 4 .

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( [link] ) Find the product. x 2 ( x 3 ) ( x + 4 ) .

x 4 + x 3 12 x 2

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( [link] ) Find the product. ( 5 m 3 n ) 2 .

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( [link] ) Solve the equation 5 ( 2 x 1 ) 4 ( x + 7 ) = 0 .

x = 11 2

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( [link] ) Factor x 5 8 x 4 + 7 x 3 .

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Questions & Answers

Three charges q_{1}=+3\mu C, q_{2}=+6\mu C and q_{3}=+8\mu C are located at (2,0)m (0,0)m and (0,3) coordinates respectively. Find the magnitude and direction acted upon q_{2} by the two other charges.Draw the correct graphical illustration of the problem above showing the direction of all forces.
Kate Reply
To solve this problem, we need to first find the net force acting on charge q_{2}. The magnitude of the force exerted by q_{1} on q_{2} is given by F=\frac{kq_{1}q_{2}}{r^{2}} where k is the Coulomb constant, q_{1} and q_{2} are the charges of the particles, and r is the distance between them.
Muhammed
What is the direction and net electric force on q_{1}= 5µC located at (0,4)r due to charges q_{2}=7mu located at (0,0)m and q_{3}=3\mu C located at (4,0)m?
Kate Reply
what is the change in momentum of a body?
Eunice Reply
what is a capacitor?
Raymond Reply
Capacitor is a separation of opposite charges using an insulator of very small dimension between them. Capacitor is used for allowing an AC (alternating current) to pass while a DC (direct current) is blocked.
Gautam
A motor travelling at 72km/m on sighting a stop sign applying the breaks such that under constant deaccelerate in the meters of 50 metres what is the magnitude of the accelerate
Maria Reply
please solve
Sharon
8m/s²
Aishat
What is Thermodynamics
Muordit
velocity can be 72 km/h in question. 72 km/h=20 m/s, v^2=2.a.x , 20^2=2.a.50, a=4 m/s^2.
Mehmet
A boat travels due east at a speed of 40meter per seconds across a river flowing due south at 30meter per seconds. what is the resultant speed of the boat
Saheed Reply
50 m/s due south east
Someone
which has a higher temperature, 1cup of boiling water or 1teapot of boiling water which can transfer more heat 1cup of boiling water or 1 teapot of boiling water explain your . answer
Ramon Reply
I believe temperature being an intensive property does not change for any amount of boiling water whereas heat being an extensive property changes with amount/size of the system.
Someone
Scratch that
Someone
temperature for any amount of water to boil at ntp is 100⁰C (it is a state function and and intensive property) and it depends both will give same amount of heat because the surface available for heat transfer is greater in case of the kettle as well as the heat stored in it but if you talk.....
Someone
about the amount of heat stored in the system then in that case since the mass of water in the kettle is greater so more energy is required to raise the temperature b/c more molecules of water are present in the kettle
Someone
definitely of physics
Haryormhidey Reply
how many start and codon
Esrael Reply
what is field
Felix Reply
physics, biology and chemistry this is my Field
ALIYU
field is a region of space under the influence of some physical properties
Collete
what is ogarnic chemistry
WISDOM Reply
determine the slope giving that 3y+ 2x-14=0
WISDOM
Another formula for Acceleration
Belty Reply
a=v/t. a=f/m a
IHUMA
innocent
Adah
pratica A on solution of hydro chloric acid,B is a solution containing 0.5000 mole ofsodium chlorid per dm³,put A in the burret and titrate 20.00 or 25.00cm³ portion of B using melting orange as the indicator. record the deside of your burret tabulate the burret reading and calculate the average volume of acid used?
Nassze Reply
how do lnternal energy measures
Esrael
Two bodies attract each other electrically. Do they both have to be charged? Answer the same question if the bodies repel one another.
JALLAH Reply
No. According to Isac Newtons law. this two bodies maybe you and the wall beside you. Attracting depends on the mass och each body and distance between them.
Dlovan
Are you really asking if two bodies have to be charged to be influenced by Coulombs Law?
Robert
like charges repel while unlike charges atttact
Raymond
What is specific heat capacity
Destiny Reply
Specific heat capacity is a measure of the amount of energy required to raise the temperature of a substance by one degree Celsius (or Kelvin). It is measured in Joules per kilogram per degree Celsius (J/kg°C).
AI-Robot
specific heat capacity is the amount of energy needed to raise the temperature of a substance by one degree Celsius or kelvin
ROKEEB
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Source:  OpenStax, Elementary algebra. OpenStax CNX. May 08, 2009 Download for free at http://cnx.org/content/col10614/1.3
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