<< Chapter < Page Chapter >> Page >

Watermelon drop A watermelon is dropped from the tenth story of a building. Solve the equation −16 t 2 + 144 = 0 for t to find the number of seconds it takes the watermelon to reach the ground.

Got questions? Get instant answers now!

Writing exercises

Explain how you solve a quadratic equation. How many answers do you expect to get for a quadratic equation?

Answers may vary.

Got questions? Get instant answers now!

Give an example of a quadratic equation that has a GCF and none of the solutions to the equation is zero.

Got questions? Get instant answers now!

Self check

After completing the exercises, use this checklist to evaluate your mastery of the objectives of this section.

This table has the following statements all to be preceded by “I can…”. The first row is “solve quadratic equations by using the zero product property”. The second row is “solve quadratic equations by factoring”. The third row is “solve applications modeled by quadratic equations”. In the columns beside these statements are the headers, “confidently”, “with some help”, and “no-I don’t get it!”.

Overall, after looking at the checklist, do you think you are well-prepared for the next section? Why or why not?

7.1 Greatest Common Factor and Factor by Grouping

Find the Greatest Common Factor of Two or More Expressions

In the following exercises, find the greatest common factor.

Factor the Greatest Common Factor from a Polynomial

In the following exercises, factor the greatest common factor from each polynomial.

24 x 42

6 ( 4 x 7 )

Got questions? Get instant answers now!

15 m 4 + 6 m 2 n

3 m 2 ( 5 m 2 + 2 n )

Got questions? Get instant answers now!

Factor by Grouping

In the following exercises, factor by grouping.

a x a y + b x b y

( a + b ) ( x y )

Got questions? Get instant answers now!

x 2 y x y 2 + 2 x 2 y

Got questions? Get instant answers now!

x 2 + 7 x 3 x 21

( x 3 ) ( x + 7 )

Got questions? Get instant answers now!

4 x 2 16 x + 3 x 12

Got questions? Get instant answers now!

m 3 + m 2 + m + 1

( m 2 + 1 ) ( m + 1 )

Got questions? Get instant answers now!

7.2 Factor Trinomials of the form x 2 + b x + c

Factor Trinomials of the Form x 2 + b x + c

In the following exercises, factor each trinomial of the form x 2 + b x + c .

u 2 + 17 u + 72

( u + 8 ) ( u + 9 )

Got questions? Get instant answers now!

k 2 16 k + 60

( k 6 ) ( k 10 )

Got questions? Get instant answers now!

y 2 + 6 y 7

( y + 7 ) ( y 1 )

Got questions? Get instant answers now!

s 2 2 s 8

( s 4 ) ( s + 2 )

Got questions? Get instant answers now!

Factor Trinomials of the Form x 2 + b x y + c y 2

In the following examples, factor each trinomial of the form x 2 + b x y + c y 2 .

x 2 + 12 x y + 35 y 2

( x + 5 y ) ( x + 7 y )

Got questions? Get instant answers now!

a 2 + 4 a b 21 b 2

( a + 7 b ) ( a 3 b )

Got questions? Get instant answers now!

p 2 5 p q 36 q 2

Got questions? Get instant answers now!

7.3 Factoring Trinomials of the form a x 2 + b x + c

Recognize a Preliminary Strategy to Factor Polynomials Completely

In the following exercises, identify the best method to use to factor each polynomial.

y 2 17 y + 42

Undo FOIL

Got questions? Get instant answers now!

8 a 3 + 72 a

Factor the GCF

Got questions? Get instant answers now!

4 m m n 3 n + 12

Got questions? Get instant answers now!

Factor Trinomials of the Form a x 2 + b x + c with a GCF

In the following exercises, factor completely.

6 x 2 + 42 x + 60

6 ( x + 2 ) ( x + 5 )

Got questions? Get instant answers now!

3 n 4 12 n 3 96 n 2

3 n 2 ( n 8 ) ( n + 4 )

Got questions? Get instant answers now!

Factor Trinomials Using the “ac” Method

In the following exercises, factor.

2 x 2 + 9 x + 4

( x + 4 ) ( 2 x + 1 )

Got questions? Get instant answers now!

18 a 2 9 a + 1

( 3 a 1 ) ( 6 a 1 )

Got questions? Get instant answers now!

15 p 2 + 2 p 8

( 5 p + 4 ) ( 3 p 2 )

Got questions? Get instant answers now!

40 s 2 s 6

( 5 s 2 ) ( 8 s + 3 )

Got questions? Get instant answers now!

Factor Trinomials with a GCF Using the “ac” Method

In the following exercises, factor.

3 x 2 + 3 x 36

3 ( x + 4 ) ( x 3 )

Got questions? Get instant answers now!

60 y 2 85 y 25

5 ( 4 y + 1 ) ( 3 y 5 )

Got questions? Get instant answers now!

7.4 Factoring Special Products

Factor Perfect Square Trinomials

In the following exercises, factor.

25 x 2 + 30 x + 9

( 5 x + 3 ) 2

Got questions? Get instant answers now!

36 a 2 84 a b + 49 b 2

( 6 a 7 b ) 2

Got questions? Get instant answers now!

64 r 2 176 r s + 121 s 2

Got questions? Get instant answers now!

40 x 2 + 360 x + 810

10 ( 2 x + 9 ) 2

Got questions? Get instant answers now!

2 y 3 16 y 2 + 32 y

2 y ( y 4 ) 2

Got questions? Get instant answers now!

5 k 3 70 k 2 + 245 k

Got questions? Get instant answers now!

Factor Differences of Squares

In the following exercises, factor.

81 r 2 25

( 9 r 5 ) ( 9 r + 5 )

Got questions? Get instant answers now!

169 m 2 n 2

( 13 m + n ) ( 13 m n )

Got questions? Get instant answers now!

25 p 2 1

( 5 p 1 ) ( 5 p + 1 )

Got questions? Get instant answers now!

9 121 y 2

( 3 + 11 y ) ( 3 11 y )

Got questions? Get instant answers now!

20 x 2 125

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

Got questions? Get instant answers now!

49 u 3 9 u

u ( 7 u + 3 ) ( 7 u 3 )

Got questions? Get instant answers now!

Factor Sums and Differences of Cubes

In the following exercises, factor.

a 3 125

( a 5 ) ( a 2 + 5 a + 25 )

Got questions? Get instant answers now!

2 m 3 + 54

2 ( m + 3 ) ( m 2 3 m + 9 )

Got questions? Get instant answers now!

7.5 General Strategy for Factoring Polynomials

Recognize and Use the Appropriate Method to Factor a Polynomial Completely

In the following exercises, factor completely.

24 x 3 + 44 x 2

4 x 2 ( 6 x + 11 )

Got questions? Get instant answers now!

16 n 2 56 m n + 49 m 2

( 4 n 7 m ) 2

Got questions? Get instant answers now!

5 r 2 + 22 r 48

( r + 6 ) ( 5 r 8 )

Got questions? Get instant answers now!

n 4 81

( n 2 + 9 ) ( n + 3 ) ( n 3 )

Got questions? Get instant answers now!

5 x 2 + 5 x 60

5 ( x 3 ) ( x + 4 )

Got questions? Get instant answers now!

m 3 + 125

( m + 5 ) ( m 2 5 m + 25 )

Got questions? Get instant answers now!

2 b 2 2 b c + 5 c b 5 c 2

Got questions? Get instant answers now!

7.6 Quadratic Equations

Use the Zero Product Property

In the following exercises, solve.

( a 3 ) ( a + 7 ) = 0

a = 3 a = −7

Got questions? Get instant answers now!

( b 3 ) ( b + 10 ) = 0

Got questions? Get instant answers now!

3 m ( 2 m 5 ) ( m + 6 ) = 0

m = 0 m = −3 m = 5 2

Got questions? Get instant answers now!

7 n ( 3 n + 8 ) ( n 5 ) = 0

Got questions? Get instant answers now!

Solve Quadratic Equations by Factoring

In the following exercises, solve.

x 2 + 9 x + 20 = 0

x = −4 , x = −5

Got questions? Get instant answers now!

2 p 2 11 p = 40

p = 5 2 , p = 8

Got questions? Get instant answers now!

144 m 2 25 = 0

m = 5 12 , m = 5 12

Got questions? Get instant answers now!

Solve Applications Modeled by Quadratic Equations

In the following exercises, solve.

The product of two consecutive numbers is 462 . Find the numbers.

−21 , −22 21 , 22

Got questions? Get instant answers now!

The area of a rectangular shaped patio 400 square feet. The length of the patio is 9 feet more than its width. Find the length and width.

Got questions? Get instant answers now!

Practice test

In the following exercises, find the Greatest Common Factor in each expression.

14 y 42

7 ( y 6 )

Got questions? Get instant answers now!

80 a 2 + 120 a 3

40 a 2 ( 2 + 3 a )

Got questions? Get instant answers now!

5 m ( m 1 ) + 3 ( m 1 )

Got questions? Get instant answers now!

In the following exercises, factor completely.

x 2 + 13 x + 36

( x + 7 ) ( x + 6 )

Got questions? Get instant answers now!

3 a 3 6 a 2 72 a

3 a ( a 2 2 a 14 )

Got questions? Get instant answers now!

5 n 2 + 30 n + 45

5 ( n + 1 ) ( n + 5 )

Got questions? Get instant answers now!

x y 8 y + 7 x 56

( x 8 ) ( y + 7 )

Got questions? Get instant answers now!

9 s 2 12 s + 4

( 3 s 2 ) 2

Got questions? Get instant answers now!

100 a 2

( 10 a ) ( 10 + a )

Got questions? Get instant answers now!

3 x 2 75 y 2

3 ( x + 5 y ) ( x 5 y )

Got questions? Get instant answers now!

a b 3 b 2 a + 6

( a 3 ) ( b 2 )

Got questions? Get instant answers now!

8 m 2 + 22 m + 5

( 4 m + 1 ) ( 2 m + 5 )

Got questions? Get instant answers now!

In the following exercises, solve.

y 2 = y + 132

y = −11 , y = 12

Got questions? Get instant answers now!

9 b 2 9 = 0

b = 1 , b = −1

Got questions? Get instant answers now!

4 n 2 + 19 + 21 = 0

n = 7 4 , n = −3

Got questions? Get instant answers now!

( x 3 ) ( x + 2 ) = 6

Got questions? Get instant answers now!

The product of two consecutive integers is 156 . Find the integers.

12 and 13 ; 13 and −12

Got questions? Get instant answers now!

The area of a rectangular place mat is 168 square inches. Its length is two inches longer than the width. Find the length and width of the placemat.

Got questions? Get instant answers now!

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
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply
Practice Key Terms 2

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Elementary algebra. OpenStax CNX. Jan 18, 2017 Download for free at http://cnx.org/content/col12116/1.2
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

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

Ask