lesson 7.1 skills practice - kyrene school district€¦ · · 2016-02-15452 chapter 7 skills...

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Lesson 7.1 Skills Practice

Name Date

The PlayoffsGraphing Inequalities

Vocabulary

Define the term in your own words

1. half-plane

A half-plane is half of a coordinate plane which represents the graph of a linear inequality. A line determined by the inequality divides the plane into two half-planes and the inequality symbol indicates which half-plane contains the solutions.

Problem Set

Write a linear inequality in two variables to represent each problem situation.

1. Tanya is baking zucchini muffins and pumpkin muffins for a school event. She needs at least 500 muffins for the event.

x 1 y 500

2. Hiro needs to buy new pens and pencils for school. Pencils cost $1 each and pens cost $2.50 each. He has $10 to spend.

x 1 2.5y 10

3. Patti makes decorative flower pots. It costs her $20 to purchase the materials for each pot. She wants to charge more than $6 per hour of labor plus her materials cost for each pot.

y . 6x 1 20

4. Jose and Devon are working on a construction job together. Devon can put in 4 times as many hours per week as Jose. Together they must work at least 80 hours per week.

4x 1 y 80

5. The Foxes are playing the Titans. The Titans have been scoring 28 or more points per game this season. Between 7-point touchdowns and 3-point field goals, the Foxes need to score more than the Titan’s lowest score to have a hope of winning the game.

7x 1 3y . 28

Chapter 7 Skills Practice 449

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450 Chapter 7 Skills Practice

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Lesson 7.1 Skills Practice page 2

6. Jack made twice his fundraising goal, which was less than the total that Cameron raised. Cameron raised $14 more than 5 times her goal.

2y , 5x 1 14

Tell whether the graph of each linear inequality will have a dashed line or a solid line. Explain your reasoning.

7. x 2 3y # 32

The line will be solid because the symbol is .

8. 8y 1 7x . 15

The line will be dashed because the symbol is ..

9. y , 14x 1 9

The line will be dashed because the symbol is ,.

10. 25.2y 2 8.3x # 228.6


11. 2 __ 3 x 1 4 __

9 y $ 3


12. y 2 17 . x 1 8

The line will be dashed because the symbol is ..

13. 185x 1 274y $ 65


14. 36 , 9y 2 2x

The line will be dashed because the symbol is ,.

For each inequality, use the test point (0, 0) to determine which half-plane should be shaded.

15. 5x 1 7y . 213

5(0) 1 7(0) . 213

0 . 213

The half-plane that includes (0, 0) should be shaded because the inequality is true for that point.

16. y 2 30 # 9x

0 2 30 9(0)

230 0


17. 28y . 6x 1 12

28(0) . 6(0) 1 12

0 Ú 12

The half-plane that does not include (0, 0) should be shaded because the inequality is false for that point.

18. 46 $ 25y 1 10x

46 25(0) 1 10(0)

46 0


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Name Date

19. 31.9x 1 63.7y , 244.5

31.9(0) 1 63.7(0) , 244.5

0 Ò 244.5


20. y 2 5 __ 6

. 1 __ 2 x 1 1 __

3

0 2 5 __ 6 . 1 __

2 (0) 1 1 __

3

2 5 __ 6 Ú 1 __

3


Graph each linear inequality.

21. y , 4x 1 2

x

y

28

26

24

22

2

4

6

8

2224 20 4 62628 8

22. y $ 10 2 x

x

y

28

26

24

22

2

4

6

8

2224 20 4 62628 8

23. y $ 1 __ 2 x 2 3

x

y

28

26

24

22

2

4

6

8

2224 20 4 62628 8

24. 2x 1 y . 1 → y . x 1 1

x

y

28

26

24

22

2

4

6

8

2224 20 4 62628 8

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25. 3x 2 4y $ 8 → y 3 __ 4 x 2 2

x

y

28

26

24

22

2

4

6

8

2224 20 4 62628 8

26. 3 __ 8 y 2 1 __

4 x , 3 __

4 → y , 2 __

3 x 1 2

x

y

28

26

24

22

2

4

6

8

2224 20 4 62628 8

Graph each inequality and determine if the ordered pair is a solution for the problem situation.

27. Marcus has 50 tokens to spend at the school carnival. The Ferris wheel costs 7 tokens and the carousel costs 5 tokens. The inequality 7x 1 5y # 50 represents the possible ways Marcus could use his tokens on the two rides. Is the ordered pair (6, 3) a solution for the problem situation?

No. The ordered pair (6, 3) is not a solution to the inequality. It is not in the shaded half-plane.

28. Sophia has $2 to buy oranges and apples. Oranges cost $0.45 each and apples cost $0.25 each. The inequality 0.45x 1 0.25y # 2 represents the possible ways Sophia could spend her $2. Is the ordered pair (2, 3) a solution for the problem situation?

Yes. The ordered pair (2, 3) is a solution to the inequality. It is in the shaded half-plane.

28 26 24 22 0 2

2

22

24

26

28

4

6

8

4 6 8x

y

Number of Ferris Wheel Rides

Num

ber

of C

arou

sel R

ides

28 26 24 22 0 2

2

22

24

26

28

4

6

8

4 6 8x

y

Number of Oranges

Num

ber

of A

pp

les

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Name Date

29. Noah plays football. His team’s goal is to score at least 15 points per game. A touchdown is worth 6 points and a field goal is worth 3 points. Noah’s league does not allow teams to try for the extra point after a touchdown. The inequality 6x 1 3y $ 15 represents the possible ways Noah’s team could score points to reach their goal. Is the ordered pair (6, 21) a solution for the problem situation?

No. The ordered pair (6, 21) is not a solution for the problem situation. It is in the correct shaded half-plane, but it is not a reasonable answer because Noah’s team cannot score a negative number of field goals.

30. Lea has $5 to buy notebooks and pens. Notebooks cost $1.25 each and pens cost $0.75 each. The inequality 1.25x 1 0.75y # 5 represents the possible ways Lea could spend her $5. Is the ordered pair (5, 2) a solution for the problem situation?

No. The ordered pair (5, 2) is not a solution to the inequality. It is not in the shaded half-plane.

Number of Touchdowns

Num

ber

of F

ield

Goa

ls

28 26 24 22 0 2

2

22

24

26

28

4

6

8

4 6 8x

y

Number of Notebooks

Num

ber

of P

ens

28 26 24 22 0 2

2

22

24

26

28

4

6

8

4 6 8x

y

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31. Leon has $10 to buy squash and carrots. Squash cost $1.50 each and carrots cost $2.75 per bunch. The inequality 1.50x 1 2.75y # 10 represents the possible ways Leon could spend his $10. Is the ordered pair (22, 4) a solution for the problem situation?

No. The ordered pair (22, 4) is not a solution for the problem situation. It is in the correct shaded half-plane, but it is not a reasonable answer because Leon cannot purchase a negative nmber of squash.

32. Olivia makes and sells muffins and scones at a school bake sale. She sells muffins for $0.50 each and scones for $0.80 each. She hopes to raise at least $20. The inequality 0.50x 1 0.80y $ 20 represents the possible ways Olivia could reach her goal. Is the ordered pair (20, 32) a solution for the problem situation?

Yes. The ordered pair (20, 32) is a solution to the inequality. It is in the shaded half-plane.

Number of Squash

Num

ber

of B

unch

es o

f Car

rots

28 26 24 22 0 2

2

22

24

26

28

4

6

8

4 6 8x

y

Number of Muf�ns

Num

ber

of S

cone

s

232 216 0 16

216

232

16

32

32x

y

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Name Date

Working the SystemSystems of Linear Inequalities

Vocabulary

Define each term in your own words.

1. constraints

The inequalities in a system of linear inequalities are known as constraints because the values of the expressions are “constrained” to lie within a certain region.

2. solution of a system of linear inequalities

The solution of a system of linear inequalities is the intersection of the solutions to each inequality in the system.

Problem Set

Write a system of linear inequalities that represents each problem situation. Remember to define your variables.

1. Jamal runs the bouncy house at a festival. The bouncy house can hold a maximum of 1200 pounds at one time. He estimates that adults weigh approximately 200 pounds and children under 16 weigh approximately 100 pounds. For 1 four-minute session of bounce time, Jamal charges adults $3 each and children $2 each. Jamal hopes to charge at least $24 for each session.

x 5 the number of adults

y 5 the number of children

3x 1 2y 24

200x 1 100y 1200

2. Carlos works at a movie theater selling tickets. The theater has 300 seats and charges $7.50 for adults and $5.50 for children. The theater expects to make at least $2000 for each showing.



x 1 y 300

7.50x 1 5.50y 2000

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3. The maximum capacity for an average passenger elevator is 15 people and 3000 pounds. It is estimated that adults weigh approximately 200 pounds and children under 16 weigh approximately 100 pounds.



x 1 y 15

200x 1 100y 3000

4. Pablo’s pickup truck can carry a maximum of 1000 pounds. He is loading his truck with 20-pound bags of cement and 80-pound bags of cement. He hopes to load at least 10 bags of cement into his truck.

x 5 the number of 20-pound bags

y 5 the number of 80-pound bags

x 1 y 10

20x 1 80y 1000

5. Eiko is drawing caricatures at a fair for 8 hours. She can complete a small drawing in 15 minutes and charges $10 for the drawing. She can complete a larger drawing in 45 minutes and charges $25 for the drawing. Eiko hopes to make at least $200 at the fair.

x 5 the number of small drawings

y 5 the number of large drawings

8 hours 5 480 minutes

10x 1 25y 200

15x 1 45y 480

6. Sofia is making flower arrangements to sell in her shop. She can complete a small arrangement in 30 minutes that sells for $20. She can complete a larger arrangement in 1 hour that sells for $50. Sofia hopes to make at least $350 during her 8-hour workday.

x 5 the number of small arrangements

y 5 the number of large arrangements

8 hours 5 480 minutes

20x 1 50y 350

30x 1 60y 480

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Name Date

Determine whether each given point is a solution to the system of linear inequalities.

7. 2x 2 y . 4

2x 1 y # 7

Point: (22, 210)

2x 2 y . 4 2x 1 y 7

2(22) 2 (210) . 4 2(22) 1 (210) 4

24 1 10 . 4 2 2 10 7

6 . 4 ✓ 28 7 ✓

Yes. The point (22, 210) is a solution to the system of inequalities.

8. x 1 5y , 21

2y $ 23x 2 2

Point: (0, 21)

x 1 5y , 21 2y 23x 2 2

(0) 1 5(21) , 21 2(21) 23(0) 2 2

25 , 21 ✓ 22 22 ✓


9. 4x 1 y , 21

1 __ 2 x # 36 2 5y

Point: (3, 7)

4x 1 y , 21

4(3) 1 (7) , 21

12 1 7 , 21

19 , 21 ✓

No. The point (3, 7) is not a solution to the system of inequalities.

1 __ 2 x 36 2 5y

1 __ 2 (3) 36 2 5(7)

3 __ 2 ‹ 1 ✗

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10. 5x 1 3y . 6

22x 1 2y , 20

Point: (22, 6)

5x 1 3y . 6 22x 1 2y , 20

5(22) 1 3(6) . 6 22(22) 1 2(6) , 20

210 1 18 . 6 4 1 12 , 20

8 . 6 ✓ 16 , 20 ✓


11. 15x 1 25y $ 300

20x 1 30y # 480

Point: (14, 8)

15x 1 25y 300 20x 1 30y 480

15(14) 1 25(8) 300 20(14) 1 30(8) 480

210 1 200 300 280 1 240 480

410 300 ✓ 520 ‹ 480 ✗


12. 22.1x 1 7y $ 249.5

2y # 26.3x 1 78

Point: (10, 28)

22.1x 1 7y 249.5 2y 26.3x 1 78

22.1(10) 1 7(28) 249.5 2(28) 26.3(10) 1 78

221 2 56 249.5 8 263 1 78

277 ‡ 249.5 ✗ 8 15 ✓


Graph each system of linear inequalities and identify two solutions.

13. y 2 3x , 5

y 1 x . 3

Answers will vary.

(2, 3) and (6, 0)

28 26 24 22 0 2

2

22

24

26

28

4

6

8

4 6 8x

y

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14. y . 2x 1 3

y , 2x 2 5

No solution

15. y # 2 2 __ 3 x 1 3

y $ 3x 2 4

Answers will vary.

(1, 2) and (22, 2)

16. y , 2 1 __ 2 x 1 6

y , 2x 1 1

Answers will vary.

(3, 1) and (2, 22)

28 26 24 22 0 2

2

22

24

26

28

4

6

8

4 6 8x

y

28 26 24 22 0 2

2

22

24

26

28

4

6

8

4 6 8x

y

28 26 24 22 0 2

2

22

24

26

28

4

6

8

4 6 8x

y

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17. y $ 2 1 __ 3 x 1 4

y $ 2x 1 5

Answers will vary.

(21, 6) and (1, 10)

18. y . 24x 1 8

y , 24x 2 2

No solution

28 26 24 22 0 2

2

22

24

26

28

4

6

8

4 6 8x

y

28 26 24 22 0 2

2

22

24

26

28

4

6

8

4 6 8x

y

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Our Biggest Sale of the Season!Systems with More Than Two Linear Inequalities

Problem Set

Write a system of linear inequalities that represents each problem situation. Remember to define your variables.

1. Ronna is shopping for a winter coat. The regular price of a winter coat is between $65 and $180. The store is running a special promotion where all coats are up to 35% off the regular price. Write a system of linear inequalities that represents the amount Ronna could spend.

Let r represent the regular price.

Let s represent the amount Ronna could spend.

r 65 r 180

s 0.65r

2. Stephen is shopping for a snowboard. The regular price of a snowboard is between $120 and $425. The store is running a special promotion where all snowboards are between 25% and 75% off the regular price. Write a system of linear inequalities that represents the amount Stephen could spend.


Let s represent the amount Stephen could spend.

r 120 r 425

s 0.75r

s 0.25r

3. Ling is shopping for a gold necklace. The regular price of a necklace is between $55 and $325. The store is running a special promotion where all necklaces are between 20% and 40% off the regular price. Write a system of linear inequalities that represents the amount Ling could spend.


Let c represent the amount Ling could spend.

r 55 r 325

c 0.80r

c 0.60r


Name Date

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4. Mario is shopping for a watch. The regular price of a watch is between $45 and $120. The store is running a special promotion where all watches are at least 25% off the regular price. Write a system of linear inequalities that represents the amount Mario could spend.


Let c represent the amount Mario could spend.

r 45 r 120

c 0.75r

5. A company manufactures at most 20 mattresses each day. The company produces a twin size mattress and a queen size mattress. Its daily production goal is to produce at least 5 of each type of mattress. Write a system of linear inequalities that represents the number of each type of mattress that can be produced.

Let t represent the number of twin size mattresses produced each day.

Let q represent the number of queen size mattresses produced each day.

t 5 q 5

t 1 q 20

6. A company manufactures at most 200 tires each day. The company produces an all-weather tire and a snow tire. Its daily production goal is to produce at least 75 of each type of tire. Write a system of linear inequalities that represents the number of each type of tire that can be produced.

Let a represent the number of all-weather tires produced each day.

Let s represent the number of snow tires produced each day.

a 75 s 75

a 1 s 200

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Graph the solution set for each system of linear inequalities. Label all points of intersection of the boundary lines. Then determine a point that satisfies all of the linear inequalities in the system.

7. y # 4

2x 2 y # 10

y . 2x 2 4 8.

y $ 22

y # 4

x 1 1 . y

x 2 1 , y

28 26 24 22 0 2

2

22

24

26

28

4

6

8

4 6 8x

y

(28, 4) (7, 4)

(2, 26)

28 26 24 22 0 2

2

24

26

28

4

6

8

4 6 8x

y

(3, 4) (5, 4)

(21, 22)(23, 22)

Answers will vary.

A solution to the system of inequalities

would be (0, 0).

Answers will vary.

A solution to the system of inequalities would be (0, 0).


Name Date

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9. y # 2 1 x

y . x 2 1

2x 1 y $ 23

2x 1 1 . y 10.

y . 22

y # x 1 1

2x # y 1 3

y # 2x 1 1

y # 0

28 26 24 22 0 2

26

28

6

8

4 6 8x

y

(24, 5)

(1, 0)25–

3, 1–

3

21–2

, 3–2

22–3

25–3

,

0 1

23

24

3

4

1

2

2 3 4x

y

(3, 22)(23, 22)

(21, 22)(22, 21)

(23, 0) (21, 0)(0, 1)

(1, 0)

Answers will vary.


Answers will vary.


11.

y . 22

y # 5

x $ 23

x # 1

y . 3x 1 1

12. y # 3x 1 2

y , 4 2 x

22x 1 3y # 2

3y $ 2x 2 8

28 26 24 22 0 2

26

28

6

8

2

4

4 6 8x

y

(23, 5)

(1, 5)

(1, 4)

(1, 22)(23, 22)

(23, 28)

(21, 22)

4–3

, 5

28 26 24 0

26

28

6

8

2

4

6 8x

y

(22, 24)

(2, 2)

(4, 0)

24–7

, 2–7

1–2

, 7–2

Answers will vary.


Answers will vary.


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Analyze the solution set for the system of linear inequalities to answer each question.

Pedro is shopping for a surfboard. The regular price of a surfboard is between $200 and $400. The store is running a special promotion where all surfboards are between 20% and 60% off the regular price. The system of linear inequalities represents the amount Pedro can save.


Let s represent the amount Pedro can save.

r $ 200 r # 400

s # 0.60r

s $ 0.20r

13. What is the most that Pedro can save?

The most Pedro can save is $240 represented by the point (400, 240).

14. What is the least that Pedro can save?

The least Pedro can save is $40 represented by the point (200, 40).

15. What is the most that Pedro will pay for the most expensive surfboard?

The least amount Pedro will save on the most expensive surfboard is $80 as represented by the point (400, 80).

400 2 80 5 320

So, the most he will pay is $320.

0 100 200Regular Price (dollars)

Sav

ings

(dol

lars

)

300 400

y

x

200

100

300

400

(200, 120)

(400, 240)

(400, 80)

(200, 40)


Name Date

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16. What is the most that Pedro will pay for the least expensive surfboard?

The least amount Pedro will save on the least expensive surfboard is $40 as represented by the point (200, 40).

200 2 40 5 160

So, the most he will pay is $160.

17. What is the least that Pedro will pay for the most expensive surfboard?

The most Pedro will save on the most expensive surfboard is $240 as represented by the point (400, 240).

400 2 240 5 160

So, the least he will pay is $160.

18. What is the least that Pedro will pay for the least expensive surfboard?

The most Pedro will save on the least expensive surfboard is $120 as represented by the point (200, 120).

200 2 120 5 80

So, the least he will pay is $80.


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Take It to the Max . . . or MinLinear Programming

Vocabulary

Define the term in your own words.

1. linear programming

Linear programming is a branch of mathematics that determines the maximum and minimum value of linear expressions on a region produced by a system of linear inequalities.

Problem Set

Write a system of linear inequalities to represent each problem situation. Remember to define your variables.

1. A company is manufacturing two different models of lamps, a table lamp and a floor lamp. A table lamp takes 1 hour to make and a floor lamp takes 2 hours to make. The company has 9 employees working 8-hour days. The total manufacturing capacity is 40 lamps per day.

Let t represent the number of table lamps.

Let f represent the number of floor lamps.

9 employees 3 8 hours per day 5 72 work hours per day

t 0 f 0

t 1 f 40

t 1 2f 72

2. A company is manufacturing calculators. A financial calculator costs $65 to make and a graphing calculator costs $105 to make. The budget available for materials is $2500 per day. The manufacturing capacity is 20 calculators per day.

Let f represent the number of financial calculators.

Let g represent the number of graphing calculators.

f 0 g 0

f 1 g 20

65f 1 105g 2500


Name Date

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3. A company is manufacturing computers. A tablet computer costs $300 to make and a laptop computer costs $600 to make. The budget available for materials is $20,000 per day. The manufacturing capacity is 50 computers per day.

Let t represent the number of tablet computers.

Let p represent the number of laptop computers.

t 0 p 0

t 1 p 50

300t 1 600p 20,000

4. A furniture company is manufacturing sofas and loveseats. A loveseat takes 5 hours and $650 to make. A sofa takes 8 hours and $950 to make. The company has 30 employees working 8-hour days. The daily operating budget is $25,000 per day for materials to make at most 40 pieces of furniture.

Let s represent the number of sofas.

Let v represent the number of loveseats.


s 0 v 0

8s 1 5v 240

950s 1 650v 25,000

s 1 v 40

5. An electronics company is manufacturing headphones. In-ear headphones take 2 hours and $65 to make. Around-ear headphones take 3 hours and $85 to make. The company has 14 employees working 12-hour days. The daily operating budget is $5000 per day for materials to make at most 65 pairs of headphones.

Let i represent the number of pairs of in-ear headphones.

Let a represent the number of pairs of around-ear headphones.


i 0 a 0

2i 1 3a 168

65i 1 85a 5000

i 1 a 65

6. A company is manufacturing golf clubs. A putter takes 2 hours and $80 to make. A driver takes 2 hours and $120 to make. The company has 6 employees working 12 hour days. The daily operating budget is $3000 per day for materials. The company wants to make at least 10 of each kind of club per day.

Let p represent the number of putters.

Let d represent the number of drivers.


p 10

d 10

2p 1 2d 72

80p 1 120d 3000

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Name Date

Graph the solution set for each system of linear inequalities. Label all points of intersection of the boundary lines.

7. y $ 0

x $ 0

3x 1 y # 18

x 1 3y # 30

0 2 4 6 8 10 12 14 16 18

y

x

8

2

4

6

12

14

16

18

(3, 9)(0, 10)

(6, 0)

8. y $ 0

x $ 0

x 1 y # 20

4x 1 9y # 135

0 2 4 6 8 10 12 14 16 18x

y

8

10

2

4

6

12

14

16

18

(9, 11)

(0, 15)

(20, 0)

9. y $ 15

x $ 10

3x 1 2y # 90

x 1 2y # 70

0 10 20 30 40 50 60 70 80 90x

40(10, 30)

(10, 15) (20, 15)

50

20

30

60

70

80

90

y

10. y $ 10

x $ 20

x 1 y # 90

x 1 4y # 240

0 10 20 30 40 50 60 70 80 90

y

40

50

10

20

30

60

70

80

90

x

(40, 50)(20, 55)

(20, 10)(80, 10)

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11. y $ 0

x $ 0

x 1 y # 26

x 1 4y # 80

0 4 8 12 16 20 24 28 32 36

y

16

4

8

12

24

28

32

36

x

(8, 18)

(26, 0)

(0, 20)

12. y $ 14

x $ 10

x 1 5y # 130

2x 1 5y # 150

0 4 8 12 16 20 24 28 32 36

y

16

20

4

8

12

24

28

32

36

x

(20, 22)

(10, 14) (40, 14)

(10, 24)

Analyze the solution set for the system of linear inequalities to answer each question.

An electronics company is manufacturing electronic book readers. A basic model takes 4 hours and $40 to make. A touch screen model takes 6 hours and $120 to make. The company has 10 employees working 12-hour days. The daily operating budget is $1920 per day for materials. The company would like at least 3 basic models and 8 touch screen models produced per day. The system of linear inequalities represents the problem situation. The graph shows the solution set for the system of linear inequalities.

Let x represent the number of basic models.

Let y represent the number of touch screen models.

y $ 8

x $ 3

4x 1 6y # 120

40x 1 120y # 1920

0 2 4 6 8 10Basic Models

12 14 16 18

y

x

8

10

2

4

6

12

16

18

Touc

h S

cree

n M

odel

s

(12, 12)(3, 15)

(3, 8) (18, 8)

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13. How many of each model should the company produce to minimize their daily cost?

C(x, y) 5 40x 1 120y

C(3, 8) 5 40(3) 1 120(8) 5 1080

C(18, 8) 5 40(18) 1 120(8) 5 1680

C(3, 15) 5 40(3) 1 120(15) 5 1920

C(12, 12) 5 40(12) 1 120(12) 5 1920

The minimum daily cost is $1080. To minimize their daily cost, the company should produce 3 basic models and 8 touch screen models.

14. How many of each model should the company produce to maximize the number of work hours utilized per day?

W(x, y) 5 4x 1 6y

W(3, 8) 5 4(3) 1 6(8) 5 60

W(18, 8) 5 4(18) 1 6(8) 5 120

W(3, 15) 5 4(3) 1 6(15) 5 102

W(12, 12) 5 4(12) 1 6(12) 5 120

The maximum number of work hours utilized is 120 hours per day. To maximize the number of work hours utilized per day, the company should produce either 18 basic models and 8 touch screen models or 12 basic models and 12 touch screen models.

15. The company earns $30 for each basic model sold and $50 for each touch screen model sold. How many of each model should the company produce to maximize their profit?

P(x, y) 5 30x 1 50y

P(3, 8) 5 30(3) 1 50(8) 5 490

P(18, 8) 5 30(18) 1 50(8) 5 940

P(3, 15) 5 30(3) 1 50(15) 5 840

P(12, 12) 5 30(12) 1 50(12) 5 960

The maximum profit is $960. To maximize their profit, the company should produce 12 basic models and 12 touch screen models.

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16. How many of each model would have to be produced to maximize the company’s daily cost?

C(x, y) 5 40x 1 120y

C(3, 8) 5 40(3) 1 120(8) 5 1080

C(18, 8) 5 40(18) 1 120(8) 5 1680

C(3, 15) 5 40(3) 1 120(15) 5 1920

C(12, 12) 5 40(12) 1 120(12) 5 1920

The maximum daily cost is $1920. To maximize their daily cost, the company would need to produce either 3 basic models and 15 touch screen models or 12 basic models and 12 touch screen models.

17. How many of each model would have to be produced to minimize the number of work hours utilized per day?

W(x, y) 5 4x 1 6y

W(3, 8) 5 4(3) 1 6(8) 5 60

W(18, 8) 5 4(18) 1 6(8) 5 120

W(3, 15) 5 4(3) 1 6(15) 5 102

W(12, 12) 5 4(12) 1 6(12) 5 120

The minimum number of work hours utilized is 60 hours per day. To minimize the number of work hours utilized per day, the company should produce 3 basic models and 8 touch screen models.

18. During a special promotion, the company earns $20 for each basic model sold and $30 for each touch screen model sold. How many of each model should the company produce to maximize their profit?

P(x, y) 5 20x 1 30y

P(3, 8) 5 20(3) 1 30(8) 5 300

P(18, 8) 5 20(18) 1 30(8) 5 600

P(3, 15) 5 20(3) 1 30(15) 5 510

P(12, 12) 5 20(12) 1 30(12) 5 600

The maximum profit during the promotion is $600. To maximize their profit during the promotion, the company should produce either 18 basic models and 8 touch screen models or 12 basic models and 12 touch screen models.

8069_Skills_Ch07.indd 472 4/23/12 12:09 PM

lesson 7.1 skills practice - kyrene school district€¦ · · 2016-02-15452 chapter 7 skills...

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