Name: 
 

Chapter 3



Multiple Choice
Identify the choice that best completes the statement or answers the question.
 
 
Solve the system by graphing.
 

 1. 

mc001-1.jpg
a.
mc001-2.jpg
(–1, 3)
c.
mc001-4.jpg
(1, 3)
b.
mc001-3.jpg
(3, –1)
d.
mc001-5.jpg
(3, 1)
 

 2. 

mc002-1.jpg
a.
mc002-2.jpg
(–5, –4)
c.
mc002-4.jpg
(–4, –5)
b.
mc002-3.jpg
(–10, –19)
d.
mc002-5.jpg
(–1, –8)
 

 3. 

mc003-1.jpg
a.
mc003-2.jpg
(0, 2)
c.
mc003-4.jpg
(2, 0)
b.
mc003-3.jpg
(2, 0)
d.
mc003-5.jpg
(0, 2)
 

 4. 

mc004-1.jpg
a.
mc004-2.jpg
infinite solutions
c.
mc004-4.jpg
(0, 0)
b.
mc004-3.jpg
(0, –1)
d.
mc004-5.jpg
no solutions
 

 5. 

A rental car agency charges a flat fee of $32.00 plus $3.00 per day to rent a certain car. Another agency charges a fee of $30.50 plus $3.25 per day to rent the same car.
a.Write a system of equations to represent the cost c for renting a car at each agency for d days.
b.Using a graphing calculator, find the number of days for which the costs are the same. Round your answer to the nearest whole day.
a.
a. mc005-1.jpg
b. 11
c.
a. mc005-3.jpg
b. 6
b.
a. mc005-2.jpg
b. 6
d.
a. mc005-4.jpg
b. 11
 

 6. 

 
A
B
C
1
Month
Revenue
Expenses
2
Jan
4000
22,000
3
Feb
9000
24,000
4
Mar
13,000
25,000
5
Apr
16,000
27,000
6
May
21,000
30,000

a.The spreadsheet shows the monthly revenue and expenses for a new business. Use your graphing calculator to find a linear model for monthly revenue and a linear model for monthly expenses.
b.Use the models to predict the month in which revenue will equal expenses.
a.
a. mc006-1.jpg
b. October
c.
a. mc006-3.jpg
b. August
b.
a. mc006-2.jpg
b. September
d.
a. mc006-4.jpg
b. September
 
 
Without graphing, classify each system as independent, dependent, or inconsistent.
 

 7. 

mc007-1.jpg
a.
dependent
b.
inconsistent
c.
independent
 

 8. 

mc008-1.jpg
a.
independent
b.
inconsistent
c.
dependent
 

 9. 

mc009-1.jpg
a.
independent
b.
inconsistent
c.
dependent
 

 10. 

An independent system of two linear equations ____ has an infinite number of solutions.
a.
always
b.
sometimes
c.
never
 
 
Solve the system by the method of substitution.
 

 11. 

mc011-1.jpg
a.
(0, –5)
b.
(–5, 0)
c.
(5, 1)
d.
(1, 5)
 

 12. 

mc012-1.jpg
a.
(–2, 24)
c.
(24, –2)
b.
(24, 2)
d.
(–24, –2)
 

 13. 

mc013-1.jpg
a.
(2, 1, –1)
b.
(2, –1, 1)
c.
(–2, 1, 1)
d.
(2, 1, 1)
 

 14. 

mc014-1.jpg
a.
(–1, –6, –1)
b.
(1, –6, 1)
c.
(–1, –6, 1)
d.
(–1, 6, 1)
 

 15. 

A group of 52 people attended a ball game. There were three times as many children as adults in the group. Set up a system of equations that represents the numbers of adults and children who attended the game and solve the system to find the number of children who were in the group.
a.
mc015-1.jpg; 39 adults; 25 children
c.
mc015-3.jpg; 25 adults; 39 children
b.
mc015-2.jpg; 39 adults, 13 children
d.
mc015-4.jpg; 13 adults, 39 children
 

 16. 

The length of a rectangle is 7.8 cm more than 4 times the width. If the perimeter of the rectangle is 94.6 cm, what are its dimensions?
a.
length = 7.9 cm; width = 39.4 cm
c.
length = 39.4 cm; width = 15.7 cm
b.
length = 23.8 cm; width = 15.7 cm
d.
length = 39.4 cm; width = 7.9 cm
 
 
Use the elimination method to solve the system.
 

 17. 

mc017-1.jpg
a.
(3, 5)
b.
(5, 3)
c.
(–3, –5)
d.
(–5, –3)
 

 18. 

mc018-1.jpg
a.
(0, –2)
b.
(–2, 0)
c.
(–2, 2)
d.
(2, –2)
 

 19. 

mc019-1.jpg
a.
f = –7, g = 5
c.
f = 5, g = 7
b.
f = –5, g = –7
d.
f = 5, g = –7
 

 20. 

mc020-1.jpg
a.
mc020-2.jpg
b.
mc020-3.jpg
c.
mc020-4.jpg
d.
mc020-5.jpg
 

 21. 

mc021-1.jpg
a.
infinite solutions
c.
(5, –2)
b.
(–5, 2)
d.
no solutions
 

 22. 

mc022-1.jpg
a.
(5, –6)
c.
(–5, 6)
b.
no solutions
d.
infinite solutions
 

 23. 

mc023-1.jpg
a.
(1, –3, 1)
b.
(1, 3, 1)
c.
(–1, 3, 1)
d.
(1, 3, –1)
 

 24. 

mc024-1.jpg
a.
(1, 8, 0)
b.
(–3, –2, –5)
c.
(1, 11, 5)
d.
(–1, 3, 4)
 

 25. 

mc025-1.jpg
a.
(1, –7, –2)
b.
(–3, 0, 5)
c.
(–3, –7, –4)
d.
(3, 5, –4)
 
 
Solve the system of inequalities by graphing.
 

 26. 

mc026-1.jpg
a.
mc026-2.jpg
c.
mc026-4.jpg
b.
mc026-3.jpg
d.
mc026-5.jpg
 

 27. 

mc027-1.jpg
a.
mc027-2.jpg
c.
mc027-4.jpg
b.
mc027-3.jpg
d.
mc027-5.jpg
 

 28. 

mc028-1.jpg
a.
mc028-2.jpg
c.
mc028-4.jpg
b.
mc028-3.jpg
d.
mc028-5.jpg
 

 29. 

mc029-1.jpg
a.
mc029-2.jpg
c.
mc029-4.jpg
b.
mc029-3.jpg
d.
mc029-5.jpg
 

 30. 

mc030-1.jpg
a.
mc030-2.jpg
c.
mc030-4.jpg
b.
mc030-3.jpg
d.
mc030-5.jpg
 

 31. 

mc031-1.jpg
a.
mc031-2.jpg
c.
mc031-4.jpg
b.
mc031-3.jpg
d.
mc031-5.jpg
 

 32. 

mc032-1.jpg
a.
mc032-2.jpg
c.
mc032-4.jpg
b.
mc032-3.jpg
d.
mc032-5.jpg
 

 33. 

Equivalent systems of two linear equations ____ have the same solutions.
a.
always
b.
sometimes
c.
never
 

 34. 

Your club is baking vanilla and chocolate cakes for a bake sale. They need at most 25 cakes. You cannot have more than 10 chocolate cakes. Write and graph a system of inequalities to model this system.
a.
Let x = the number of vanilla cakes.
Let y = the number of chocolate cakes.
mc034-1.jpg
mc034-2.jpg
c.
Let x = the number of vanilla cakes.
Let y = the number of chocolate cakes.
mc034-5.jpg
mc034-6.jpg
b.
Let x = the number of vanilla cakes.
Let y = the number of chocolate cakes.
mc034-3.jpg
mc034-4.jpg
d.
Let x = the number of vanilla cakes.
Let y = the number of chocolate cakes.
mc034-7.jpg
mc034-8.jpg
 

 35. 

An exam consists of two parts, Section X and Section Y. There can be a maximum of 90 questions. There must be at least 5 more questions in Section Y than in Section X. Write a system of inequalities to model the number of questions in each of the two sections. Then solve the system by graphing.
a.
mc035-1.jpgmc035-2.jpg
c.
mc035-5.jpg
mc035-6.jpg
b.
mc035-3.jpg
mc035-4.jpg
d.
mc035-7.jpg
mc035-8.jpg
 

 36. 

A system of two linear inequalities ____ has a solution.
a.
always
b.
sometimes
c.
never
 

 37. 

Find the values of x and y that maximize the objective function P = 3x + 2y for the graph. What is the maximum value?
mc037-1.jpg
a.
maximum value at (5, 4); 32
c.
maximum value at (9, 0); 27
b.
maximum value at (0, 8); 16
d.
maximum value at (0, 0); 0
 

 38. 

Given the system of constraints, name all vertices. Then find the maximum value of the given objective function.
mc038-1.jpg

Maximum for mc038-2.jpg
a.
(0, 2), (2, 0), (4, 6); maximum value of –6
b.
(0, 2), (2, 0), (6, 4); maximum value of 12
c.
(0, 2), (2, 0), (4, 2); maximum value of 10
d.
(0, 2), (2, 0), (4, 6); maximum value of 8
 

 39. 

The maximum value of a linear objective function ____ occurs at exactly one vertex of the feasible region.
a.
always
b.
sometimes
c.
never
 

 40. 

Your computer supply store sells two types of inkjet printers. The first, type A, costs $137 and you make a $50 profit on each one. The second, type B, costs $100 and you make a $40 profit on each one. You can order no more than 100 printers this month, and you need to make at least $4400 profit on them. If you must order at least one of each type of printer, how many of each type of printer should you order if you want to minimize your cost?
a.
40 of type A
60 of type B
c.
60 of type A
40 of type B
b.
30 of type A
70 of type B
d.
70 of type A
30 of type B
 

 41. 

A factory can produce two products, x and y, with a profit approximated by P = 12x + 23y – 900. The production of y can exceed x by no more than 200 units. Moreover, production levels are limited by the formula mc041-1.jpg What production levels yield maximum profit?
a.
x = 0
y = 0
b.
x = 1000
y = 0
c.
x = 0
y = 200
d.
x = 200
y = 400
 

 42. 

Describe the location of the point in coordinate space.
(–7, 6, –4)
a.
From the origin, move 7 units back, 6 units left, and 4 units down.
b.
From the origin, move 7 units back, 6 units right, and 4 units down.
c.
From the origin, move 7 units back, 6 units right, and 4 units up.
d.
From the origin, move 7 units forward, 6 units right, and 4 units down.
 

 43. 

Plot the point (–3, –1, 2) in a three-dimensional coordinate system.
a.
mc043-1.jpg
c.
mc043-3.jpg
b.
mc043-2.jpg
d.
mc043-4.jpg
 

 44. 

Find the coordinates of the point in the diagram.
mc044-1.jpg
a.
(4, –2, 1)
b.
(2, 4, 3)
c.
(4, 2, 3)
d.
(1, –4, –3)
 

 45. 

Which of the following points lies in the plane represented by mc045-1.jpg?
a.
(0, 0, 9)
b.
(–2, –7, 10)
c.
(–10, 8, 5)
d.
(4, 4, –8)
 

 46. 

Find the equation of each trace of 6x + 4y – 12z = 36.
a.
6x = 36
4y = 36
12z = 36
c.
6x + 4y = 0
4y – 12z = 0
6x – 12z = 0
b.
6x + 4y = 3
4y – 12z = 6
6x – 12z = 9
d.
6x + 4y = 36
4y – 12z = 36
6x – 12z = 36
 
 
Solve the system using either method of substitution or elimination.
 

 47. 

mc047-1.jpg
a.
(–3, 6, –2)
c.
(–3, 6, –8)
b.
(–3, 8, 0)
d.
no solution
 

 48. 

mc048-1.jpg
a.
no solution
b.
(2, –5, –2)
c.
(–2, –5, 2)
d.
(2, 5, 2)
 

 49. 

A food store makes a 9-lb mixture of peanuts, cashews, and raisins. Peanuts cost $1.50 per pound, cashews cost $2.00 per pound, and raisins cost $1.00 per pound. The mixture calls for twice as much peanuts than cashews. The total cost of the mixture is $13.00. How much of each ingredient did the store use?
a.
6 lb peanuts, 1 lb cashews, 2 lb raisins
b.
2 lb peanuts, 4 lb cashews, 3 lb raisins
c.
4 lb peanuts, 2 lb cashews, 3 lb raisins
d.
6 lb peanuts, 2 lb cashews, 1 lb raisins
 

 50. 

The solution to a system of three equations in three variables is ____ one point.
a.
always
b.
sometimes
c.
never
 

Short Answer
 

 51. 

Graph the system of constraints. Then find the values of x and y that maximize sa051-1.jpg.

sa051-2.jpg
 

 52. 

Write a second equation for the system so that the system will have no solution.
3x + 2y = –8
 

 53. 

Graph sa053-1.jpg.
sa053-2.jpg
 

 54. 

Graph sa054-1.jpg.
sa054-2.jpg
 

 55. 

Graph sa055-1.jpg.
sa055-2.jpg
 

 56. 

Graph the point (–2, 0, 4).
sa056-1.jpg
 

Essay
 

 57. 

A fish market buys tuna for $.50 per pound and spends $1.50 per pound to clean and package it. Salmon costs $2.00 per pound to buy and $2.00 per pound to clean and package. The market makes $2.50 per pound profit on tuna and $2.80 per pound profit for salmon. The market can spend only $106 per day to buy fish and $134 per day to clean it. How much of each type of fish should the market buy to maximize profit?
a.Write an objective function P and constraints for a linear program to model the problem.
b.Graph the constraint and find the coordinates of each vertex.
c.Evaluate P at each vertex to find the maximum profit.
 

 58. 

You have $50 to spend on a party. Pizzas cost $10 each, chips cost $2 per bag, and soda costs $1.25 per bottle.
a.Write an equation in three variables for the number of pizzas, bags of chips, and bottles of soda you can buy.
b.Find the intercepts of the equation.
c.Graph the equation.
es058-1.jpg
 

 59. 

Tasty Bakery sells three kinds of muffins: chocolate chip muffins for $0.65 each, oatmeal muffins for $0.70 each, and blueberry muffins for $0.75 cents each. Charles buys some of each kind and chooses three more chocolate chip muffins than blueberry muffins. If he spends $6.85 on 10 muffins, how many of each type of muffin does he buy? Write and solve a system of three equations in three variables. Show your work.
 

Other
 

 60. 

Explain how to determine whether a system is independent, dependent, or inconsistent without graphing.
 

 61. 

Explain how to solve a system of equations by substitution.
 



 
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