Title: Chapter 5 Graphs and Functions
Course: quiz duplicate error

Q: Evaluate [Image] for x = 1.
- 3
- 1
- –1
- –5
A: 1

Q: Evaluate [Image] for x = 2.
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Evaluate [Image] for x = 2.
- –8
- 8
- –4
- 6
A: 8

Q: Evaluate [Image] for x = –3.
- –12
- 6
- –18
- 18
A: –18

Q: Evaluate [Image] for x = –2.
- 2
- –2
- 6
- –14
A: –2

Q: Lena makes home deliveries of groceries for a supermarket. Her only stops after she leaves the supermarket are at traffic lights and the homes where she makes the deliveries. The graph shows her distance from the store on her first trip for the day. What is the greatest possible number of stops she made at traffic lights?

[Image]
- 3
- 4
- 9
- 5
A: 3

Q: Identify the mapping diagram that represents the relation and determine whether the relation is a function.
[Image]
- [Image] The relation is not a function.
- [Image] The relation is a function.
- [Image] The relation is a function.
- [Image] The relation is not a function.
A: [Image] The relation is a function.

Q: A plane that carries mail makes a round trip each day from Chicago to New York. It makes 1 intermediate stop on the way to New York and 1 intermediate stop on the way back to Chicago. Suppose you make a graph of the altitude of the plane for one day, with time on the horizontal axis and altitude on the vertical axis. How many times will the graph touch the horizontal axis?
- 4
- 5
- 7
- 2
A: 5

Q: Evaluate [Image] for x = –3.
- –2
- 14
- –6
- –14
A: –14

Q: Evaluate [Image] for x = 1.
- 5
- –1
- –5
- –3
A: –5

Q: Evaluate [Image] for x = 2.
- –10
- 10
- 6
- –8
A: –10

Q: Evaluate [Image] for x = –2.
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Evaluate [Image] for x = 3.
- –11
- 1
- –6
- 11
A: –11

Q: Evaluate [Image] for x = 4.
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Evaluate [Image] for x = 3.
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Which graph is the most appropriate to describe a quantity decreasing at a steady rate?
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: A plane that carries mail makes a round trip each day from Chicago to New York. It makes 3 intermediate stops on the way to New York and 1 intermediate stop on the way back to Chicago. Suppose you make a graph of the altitude of the plane for one day, with time on the horizontal axis and altitude on the vertical axis. How many times will the graph touch the horizontal axis?
- 11
- 6
- 7
- 4
A: 7

Q: Identify the mapping diagram that represents the relation and determine whether the relation is a function.
[Image]
- [Image] The relation is a function.
- [Image] The relation is a function.
- [Image] The relation is not a function
- [Image] The relation is not a function.
A: [Image] The relation is not a function.

Q: A function is ________ a relation.
- always
- sometimes
- never
A: always

Q: Evaluate [Image] for x = –6.
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Evaluate [Image] for x = 2.
- –2
- –1
- 3
- 1
A: –1

Q: The graph below shows how the cost of gasoline changes over one month. According to the graph, the cost of gasoline ________ decreases.

[Image]
- always
- sometimes
- never
A: sometimes

Q: Evaluate [Image] for x = –4.
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Graph the function.

[Image]
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: A taxi company charges passengers $1.00 for a ride, no matter how long the ride is, and an additional $0.40 for each mile traveled. The rule [Image] describes the relationship between the number of miles m and the total cost of the ride c.
a. What is the charge for a 1-mile ride?
b. What is the charge for a 2.7-mile ride?
- $0.40; $3.10
- $1.40; $2.08
- $1.00; $1.40
- $0.40; $1.08
A: $1.40; $2.08

Q: Evaluate [Image] for x = 2.
- 5
- –4
- –7
- –5
A: –7

Q: A taxi company charges passengers $2.00 for a ride, no matter how long the ride is, and an additional $0.20 for each mile traveled. The rule [Image] describes the relationship between the number of miles m and the total cost of the ride c.
a. What is the charge for a 1-mile ride?
b. What is the charge for a 2.7-mile ride?
- $2.20; $2.54
- $2.00; $2.20
- $0.20; $5.60
- $0.20; $0.54
A: $2.20; $2.54

Q: Evaluate [Image] for x = –2.
- 1
- 7
- –1
- 4
A: 7

Q: Evaluate [Image] for x = –2.
- –5
- 1
- –1
- –4
A: –5

Q: Evaluate [Image] for x = –3.
- –9
- –4
- –8
- 4
A: –8

Q: Evaluate [Image] for x = –1.
- 2
- 4
- –1
- –4
A: 2

Q: Evaluate [Image] for x = –3.
- –1
- 9
- 1
- 13
A: 13

Q: Write a function rule for the table.

x | f(x)
3 | 7
4 | 8
5 | 9
6 | 10
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Write a function rule for the table.

x | f(x)
0 | 0
1 | 4
2 | 8
3 | 12
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Write a function rule for the table.

x | f(x)
–1 | –4
0 | –3
1 | –2
2 | –1
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Write a function rule for the table.

x | f(x)
–1 | –3
0 | 0
1 | 3
2 | 6
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Write a function rule for the table.

x | f(x)
0 | 4
1 | 5
2 | 6
3 | 7
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Write a function rule for the table.

x | f(x)
–2 | –4
–1 | –2
0 | 0
1 | 2
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Write a function rule for the table.

x | f(x)
2 | –6
3 | –9
4 | –12
5 | –15
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Write a function rule for the table.

x | f(x)
2 | –8
3 | –12
4 | –16
5 | –20
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Write a function rule for the table.

x | f(x)
0 | 0
1 | –3
2 | –6
3 | –9
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Write a function rule for the table.

x | f(x)
–1 | 4
0 | 0
1 | –4
2 | –8
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Write a function rule for the table.

x | f(x)
3 | –6
4 | –8
5 | –10
6 | –12
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Write a function rule for the table.

x | f(x)
–2 | 6
–1 | 3
0 | 0
1 | –3
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Write a function rule for the table.

x | f(x)
–3 | –4
–2 | –3
–1 | –2
0 | –1
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Crystal earns $5.50 per hour mowing lawns.
a. Write a rule to describe how the amount of money m earned is a function of the number of hours h spent mowing lawns.
b. How much does Crystal earn if she works 3 hours and 45 minutes?
- [Image]; $61.50
- [Image]; $0.68
- [Image]; $18.98
- [Image]; $20.63
A: [Image]; $20.63

Q: Find the constant of variation k for the direct variation.

[Image]
- k = [Image]
- k = [Image]
- k = [Image]
- k = [Image]
A: k = [Image]

Q: A zucchini plant in Darnell’s garden was 10 centimeters tall when it was first planted. Since then, it has grown approximately 0.5 centimeters per day.
a. Write a rule to describe the function.
b. After how many days will the zucchini plant be 0.185 meters tall?
- [Image]; 17 days
- [Image]; 1.1 days
- [Image]; 4 days
- [Image]; 37 days
A: [Image]; 17 days

Q: Find the constant of variation k for the direct variation.

x | f(x)
–3 | 4.5
0 | 0
2 | –3
5 | –7.5
- k = 1.5
- k = –0.7
- k = –1
- k = –1.5
A: k = –1.5

Q: Write a function rule that gives the total cost c(p) of p pounds of sugar if each pound costs $.46.
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: A snail travels at a rate of 2.37 feet per minute.
a. Write a rule to describe the function.
b. How far will the snail travel in 6 minutes?
- [Image]; 14.22 ft
- [Image]; 14.22 ft
- [Image]; 8.37 ft
- [Image]; 2.53 ft
A: [Image]; 14.22 ft

Q: Write an equation of the direct variation that includes the point (–3, 8).
- y = [Image]x
- y = [Image]x
- y = [Image]x
- y = [Image]x
A: y = [Image]x

Q: Write a function rule that gives the total cost c(p) of p pounds of sugar if each pound costs $.43.
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Write a function rule that gives the total cost c(p) of p pounds of sugar if each pound costs $.59.
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: A snail travels at a rate of 2.46 feet per minute.
a. Write a rule to describe the function.
b. How far will the snail travel in 8 minutes?
- [Image]; 19.68 ft
- [Image]; 3.25 ft
- [Image]; 10.46 ft
- [Image]; 19.68 ft
A: [Image]; 19.68 ft

Q: Write an equation of the direct variation that includes the point (10, 4).
- y = [Image]x
- y = [Image]x
- y = [Image]x
- y = [Image]x
A: y = [Image]x

Q: Write a function rule that gives the total cost c(p) of p pounds of sugar if each pound costs $.47.
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: A snail travels at a rate of 2.49 feet per minute.
a. Write a rule to describe the function.
b. How far will the snail travel in 8 minutes?
- [Image]; 3.21 ft
- [Image]; 19.92 ft
- [Image]; 19.92 ft
- [Image]; 10.49 ft
A: [Image]; 19.92 ft

Q: Write a function rule for the table.

x | f(x)
3 | 1
4 | 2
5 | 3
6 | 4
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Write an equation of the direct variation that includes the point (–10, –19).
- y = [Image]x
- y = [Image]x
- y = [Image]x
- y = [Image]x
A: y = [Image]x

Q: Find the constant of variation k for the direct variation.

x | f(x)
–1 | 2
0 | 0
2 | –4
5 | –10
- k = –1.5
- k = 2
- k = –0.5
- k = –2
A: k = –2

Q: A zucchini plant in Darnell’s garden was 13 centimeters tall when it was first planted. Since then, it has grown approximately 0.5 centimeters per day.
a. Write a rule to describe the function.
b. After how many days will the zucchini plant be 0.195 meters tall?
- [Image]; 1.5 days
- [Image]; 3 days
- [Image]; 13 days
- [Image]; 39 days
A: [Image]; 13 days

Q: Write an equation of the direct variation that includes the point (–4, –13).
- y = [Image]x
- y = [Image]x
- y = [Image]x
- y = [Image]x
A: y = [Image]x

Q: Write a function rule that gives the total cost c(p) of p pounds of sugar if each pound costs $.36.
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Write an equation of the direct variation that includes the point (–3, 16).
- y = [Image]x
- y = [Image]x
- y = [Image]x
- y = [Image]x
A: y = [Image]x

Q: The length of a field in yards is a function f(n) of the length n in feet. Write a function rule for this situation.
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Find the constant of variation k for the direct variation.

x | f(x)
–3 | 10.5
0 | 0
2 | –7
4 | –14
- k = –3
- k = –3.5
- k = 3.5
- k = –0.3
A: k = –3.5

Q: Write an equation of the direct variation that includes the point (9, –12).
- y = [Image]x
- y = [Image]x
- y = [Image]x
- y = [Image]x
A: y = [Image]x

Q: Crystal earns $5.75 per hour mowing lawns.
a. Write a rule to describe how the amount of money m earned is a function of the number of hours h spent mowing lawns.
b. How much does Crystal earn if she works 1 hour and 15 minutes?
- [Image]; $20.75
- [Image]; $6.61
- [Image]; $7.19
- [Image]; $0.22
A: [Image]; $7.19

Q: An equation of the form [Image], where a, b, and c do not equal zero, is ________ a direct variation.
- sometimes
- always
- never
A: never

Q: Use inductive reasoning to describe the pattern. Then find the next two numbers in the pattern.

28, 23, 18, 13, . . .
- add 5 to the previous term; 18, 23
- multiply the previous term by –5; –65, 325
- multiply the previous term by –5; 8, 325
- subtract 5 from the previous term; 8, 3
A: subtract 5 from the previous term; 8, 3

Q: Find the common difference of the arithmetic sequence.

–2, [Image], [Image], [Image], . . .
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: The time t required to drive a certain distance varies inversely with the speed r. If it takes 3 hours to drive the distance at 40 miles per hour, how long will it take to drive the same distance at 35 miles per hour?
- about 3.43 hours
- about 466.67 hours
- about 2.63 hours
- 120 hours
A: about 3.43 hours

Q: Find the constant of variation k for the inverse variation. Then write an equation for the inverse variation.
y = 4.5 when x = 3
- k = 13.5; 13.5y = x
- k = 1.5; y = 1.5x
- k = 1.5; y = [Image]
- k = 13.5; xy = 13.5
A: k = 13.5; xy = 13.5

Q: Do the data in the table represent a direct variation or an inverse variation? Write an equation to model the data in the table.

x | 2 | 4 | 8 | 12
y | 2 | 1 | [Image] | [Image]
- inverse variation; xy = 4
- direct variation; y = 4x
- direct variation; y = [Image]
- inverse variation; [Image] = 4
A: inverse variation; xy = 4

Q: Use inductive reasoning to describe the pattern. Then find the next two numbers in the pattern.

5, 10, 20, 40, . . .
- multiply the previous term by 2; 80, 160
- multiply the previous term by –2; –80, 160
- subtract 5 from the previous term; 80, 160
- add 5 to the previous term; 35, 30
A: multiply the previous term by 2; 80, 160

Q: The amount of a person’s paycheck p varies directly with the number of hours worked t. For 16 hours of work, the paycheck is $124.00. Write an equation for the relationship between hours of work and pay.
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Find the common difference of the arithmetic sequence.

5, 5.3, 5.6, 5.9, . . .
- 0.3
- 1.1
- –1.1
- 10.3
A: 0.3

Q: The pair of points is on the graph of an inverse variation. Find the missing value.

(9, 5) and (x, 6)
- [Image]
- [Image]
- 45
- [Image]
A: [Image]

Q: Use inductive reasoning to describe the pattern. Then find the next two numbers in the pattern.

–5, –10, –20, –40, . . .
- multiply the previous term by 2; –80, –160
- add –5 to the previous term; –35, –30
- subtract 5 from the previous term; –80, –160
- multiply the previous term by –2; 80, –160
A: multiply the previous term by 2; –80, –160

Q: The total cost of gasoline varies directly with the number of gallons purchased. Gas costs $1.84 per gallon. Write a direct variation to model the total cost c for g gallons of gas.
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Find the common difference of the arithmetic sequence.

9, 13, 17, 21, . . .
- 4
- [Image]
- [Image]
- 22
A: 4

Q: The pair of points is on the graph of an inverse variation. Find the missing value.

(4, 2) and (x, 7)
- [Image]
- [Image]
- [Image]
- 8
A: [Image]

Q: Find the first, fourth, and tenth terms of the arithmetic sequence described by the given rule.

[Image]
- 9, 29, 81
- –7, 29, 83
- –7, 20, 74
- 0, 27, 81
A: –7, 20, 74

Q: Suppose that y varies inversely with x. Write an equation for the inverse variation.
y = 6 when x = 8
- y = [Image]
- y = 2x
- x = [Image]
- y = [Image]
A: y = [Image]

Q: Find the first, fourth, and tenth terms of the arithmetic sequence described by the given rule.

[Image]
- –6, [Image], [Image]
- 0, [Image], [Image]
- –6, [Image], [Image]
- 5, [Image], [Image]
A: –6, [Image], [Image]

Q: Find the common difference of the arithmetic sequence.

14, 11, 8, 5, . . .
- [Image]
- –3
- 25
- [Image]
A: –3

Q: The distance a spring will stretch varies directly with how much weight is attached to the spring. If a spring stretches 9 inches with 100 pounds attached, how far will it stretch with 90 pounds attached? Round to the nearest tenth of an inch.
- 8.9 in.
- 10 in.
- 8.1 in.
- 9.1 in.
A: 8.1 in.

Q: Use inductive reasoning to describe the pattern. Then find the next two numbers in the pattern.

–9, –4, 1, 6, . . .
- add 5 to the previous term; 11, 16
- multiply the previous term by 5; 30, 150
- subtract 5 from the previous term; 1, –4
- multiply the previous term by 5; 11, 150
A: add 5 to the previous term; 11, 16

Q: The pair of points is on the graph of an inverse variation. Find the missing value.

(2.4, 3) and (5, y)
- 1.44
- 1
- 6.25
- 0.69
A: 1.44

Q: Do the data in the table represent a direct variation or an inverse variation? Write an equation to model the data in the table.

x | 2 | 4 | 8 | 12
y | 6 | 3 | [Image] | [Image]
- direct variation; y = 12x
- inverse variation; xy = 12
- direct variation; y = [Image]
- inverse variation; [Image] = 12
A: inverse variation; xy = 12

Q: Do the data in the table represent a direct variation or an inverse variation? Write an equation to model the data in the table.

x | 6 | 8 | 12 | 20
y | 9 | 12 | 18 | 30
- inverse variation; xy = 1.5
- direct variation; y = [Image]x
- direct variation; y = 1.5x
- inverse variation; xy = 54
A: direct variation; y = 1.5x

Q: The distance a spring will stretch varies directly with how much weight is attached to the spring. If a spring stretches 10 inches with 70 pounds attached, how far will it stretch with 50 pounds attached? Round to the nearest tenth of an inch.
- 9.9 in.
- 10.2 in.
- 7.1 in.
- 14 in.
A: 7.1 in.

Q: The total cost of gasoline varies directly with the number of gallons purchased. Gas costs $1.89 per gallon. Write a direct variation to model the total cost c for g gallons of gas.
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: The amount of a person’s paycheck p varies directly with the number of hours worked t. For 25 hours of work, the paycheck is $206.25. Write an equation for the relationship between hours of work and pay.
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: Find the common difference of the arithmetic sequence.

2, [Image], [Image], [Image], . . .
- [Image]
- [Image]
- [Image]
- [Image]
A: [Image]

Q: The time t required to drive a certain distance varies inversely with the speed r. If it takes 2 hours to drive the distance at 30 miles per hour, how long will it take to drive the same distance at 50 miles per hour?
- 60 hours
- 1.2 hours
- 750 hours
- about 3.33 hours
A: 1.2 hours

Q: Find the common difference of the arithmetic sequence.

–4, –5.2, –6.4, –7.6, . . .
- –1.3
- 1.3
- –9.2
- –1.2
A: –1.2

Q: Find the common difference of the arithmetic sequence.

The common difference in an arithmetic sequence is ________ a positive number.
- sometimes
- always
- never
A: sometimes

Q: Find the first, fourth, and tenth terms of the arithmetic sequence described by the given rule.

[Image]
- –10, [Image], [Image]
- 0, [Image], [Image]
- 3, [Image], [Image]
- –10, [Image], [Image]
A: –10, [Image], [Image]

Q: Find the first, fourth, and tenth terms of the arithmetic sequence described by the given rule.

[Image]
- 12, 24, 42
- 0, 9, 27
- 3, 24, 27
- 12, 21, 39
A: 12, 21, 39

Q: Find the first, fourth, and tenth terms of the arithmetic sequence described by the given rule.

[Image]
- –2, –11.9, –31.7
- –3.3, –15.2, –29.7
- 0, –9.9, –29.7
- –2, –15.2, –35
A: –2, –11.9, –31.7

Q: Find the first, fourth, and tenth terms of the arithmetic sequence described by the given rule.

[Image]
- –3, –11.8, –25
- 0, –6.6, –19.8
- –3, –9.6, –22.8
- –2.2, –11.8, –19.8
A: –3, –9.6, –22.8

Q: An enclosed gas exerts a pressure P on the walls of a container. This pressure is directly proportional to the temperature T of the gas. If the pressure is 7 lb per square inch. when the temperature is 420ºF, find the constant of variation.
- 49
- [Image]
- [Image]
- 60
A: [Image]

Q: Suppose that y varies inversely with x. Write an equation for the inverse variation.
y = 4 when x = 8
- y = [Image]
- y = [Image]
- x = [Image]
- y = 4x
A: y = [Image]

Model the function rule [Image] with a table of values and a graph.

x | y
–1 |
0 |
1 |

[Image]

Use the vertical line test to determine whether the relation is a function.

[Image]
[Image]

Q: Determine whether the function rule models discrete or continuous data.

A movie store sells DVDs for $15 each. The function C(d) = 15d relates the total cost of movies to the number purchased d.
- discrete
- continuous
A: discrete

Elaine is in the business of repairing home computers. She charges a base fee of $45 for each visit and $25 per hour for her labor. The total cost c(x) for a home visit and x hours of labor is modeled by the function rule [Image]. Use the function rule to make a table of values and a graph.

x | c(x)
0 |
1 |
2 |
3 |

[Image]

Q: Determine whether the function rule models discrete or continuous data.

A produce stand sells roasted peanuts for $2.99 per pound. The function C(p) = 2.99p relates the total cost of the peanuts to the number od pounds purchased p.
- discrete
- continuous
A: continuous

During a clothing store’s Bargain Days, the regular price for T-shirts is discounted by $5. There is a state sales tax of 5%, and the $5 discount is applied before the sales tax is calculated.
a. Write an expression that shows the regular price r of a T-shirt minus the $5 discount.
b. Write a rule for the function p(r) that expresses the final price p of a T-shirt with the discount applied and sales tax added.
c. How much would you pay during Bargain Days for a shirt regularly priced at $15.50?

An employee receives a weekly salary of $340 and a 6% commission on all sales.
a. Write a rule to describe the function f(d) that gives weekly earnings in terms of d dollars in sales.
b. Find the employee’s earnings for a week with $660 total sales.
c. What were the employee’s total sales for a week in which her earnings were $1300?

For the data in the table, tell whether y varies directly with x. If it does, write an equation for the direct variation.

x | y
–1 | –0.7
0 | 0
1 | 0.7
2 | 1.4

Find the range of [Image] for the domain {–2, 0, 2, 4}.

Elaine is in the business of repairing home computers. She charges a base fee of $35 for each visit and $45 per hour for her labor. The total cost c(x) for a home visit and x hours of labor is modeled by the function rule [Image]. Use the function rule to make a table of values and a graph.

x | c(x)
0 |
1 |
2 |
3 |

[Image]

Find the range of [Image] for the domain {–3, –2, –1, 1}.

Find the range of [Image] for the domain {–2, 2, 4, 5}.

For the data in the table, tell whether y varies directly with x. If it does, write an equation for the direct variation.

x | y
0 | 0
1 | 4
2 | 8
3 | 12

The area formula for a parallelogram with area 36 is bh = 36. Does the formula represent a direct or an inverse variation? Explain.

Is the equation a direct variation? If it is, find the constant of variation.

[Image]

Is the equation a direct variation? If it is, find the constant of variation.

–x = –3y

For the data in the table, tell whether y varies directly with x. If it does, write an equation for the direct variation.

x | y
–1 | 2
0 | 1
1 | 0
2 | –1

An employee receives a weekly salary of $270 and a 3% commission on all sales.
a. Write a rule to describe the function f(d) that gives weekly earnings in terms of d dollars in sales.
b. Find the employee’s earnings for a week with $570 total sales.
c. What were the employee’s total sales for a week in which her earnings were $750?

Label each section of the graph.
[Image]

A computer consultant is thinking of renting office space in a building that charges $28 per square foot per month for office space. She estimates that electricity, telephone, and supplies will cost $500 per month.
a. Define variables and write an equation that describes the consultant’s monthly office expenses.
b. Do her monthly office expenses vary directly with the amount of office space she could rent?
c. What is the greatest amount of space she can afford if she wants to spend no more than $4000 a month on rent and other expenses? Show your work.

Is the equation a direct variation? If it is, find the constant of variation.

5x = y

A biologist records the number of microbes growing in a culture at the times listed in the table. If the microbes continue to multiply at this rate, how many will there be at 6 P.M. on the second day?

Time of Observation | Number of Microbes
Day 1, 12:00 noon | 12,000
Day 1, 6:00 P.M. | 18,000
Day 2, 12:00 midnight | 27,000
Day 2, 6:00 A.M. | 40,500

For the data in the table, tell whether y varies directly with x. If it does, write an equation for the direct variation.

x | y
2 | –6.6
3 | –9.9
4 | –13.2
5 | –16.5

For the data in the table, tell whether y varies directly with x. If it does, write an equation for the direct variation.

x | y
2 | 9
3 | 14
4 | 19
5 | 24

Sketch a graph of the speed of a city bus on a daily route. Label each section.

A - bus pulls away from a stop and increases speed
B - bus is at a constant speed between stops
C - bus is stopped
D - bus increases speed after stopping

[Image]

Find the range of [Image] for the domain {–1, 2, 3, 5}.