1. INTERMEDIATE ALGEBRA Class Notes
Sections 7.1 and 7.2

2. Section 7.1 Chapter 7: Introduction to Relations and Functions
Let’s work Exercise #19 from Section 5.1

3. Section 7.1 Exercise #7 Chapter 7:
Introduction to Relations and Functions
Section 7.1 Exercise #7
Let’s work Exercise #19 from Section 5.1

4. Write the slope-intercept form of the line.
Then identify the slope and y-intercept.

5. Section 7.1 Exercise #31 Chapter 7:
Introduction to Relations and Functions
Section 7.1 Exercise #31

8. Section 7.1 Exercise #39 Chapter 7:
Introduction to Relations and Functions
Section 7.1 Exercise #39

11. Section 7.1 Exercise #45 Chapter 7:
Introduction to Relations and Functions
Section 7.1 Exercise #45

14. Section 7.1 Exercise #55 Chapter 7:
Introduction to Relations and Functions
Section 7.1 Exercise #55

15. The following table represents the median selling price, y, of new privately-owned one-family houses sold in the Midwest from 1980 to Let x represent the number of years since Let y represent price in thousands of dollars.
Year
Price in $1000
1980 x = 0 67
1985 x = 5 84
1990 x = 10
108
1995 x = 15
142
2000 x = 20
167

16. Year (x = 0 corresponds to 1980)
200
150
100 50
Year (x = 0 corresponds to 1980)
Price (in $1000)

17. Year (x = 0 corresponds to 1980)
200
150
100 50
Year (x = 0 corresponds to 1980)
Price (in $1000)

18. Year (x = 0 corresponds to 1980)
200
150
100 50
Year (x = 0 corresponds to 1980)
Price (in $1000)

19. Year (x = 0 corresponds to 1980)
200
150
100 50
Year (x = 0 corresponds to 1980)
Price (in $1000)

20. Year (x = 0 corresponds to 1980)
200
150
100 50
Year (x = 0 corresponds to 1980)
Price (in $1000)

21. The median price in 2005 will be
$192,000.

22. Section 7.2 Applications of Linear Equations
Chapter 7:
Introduction to Relations and Functions
Section 7.2 Applications of Linear Equations
Let’s work Exercise #19 from Section 5.1

23. Section 7.2 Exercise #5 Chapter 7:
Introduction to Relations and Functions
Section 7.2 Exercise #5
Let’s work Exercise #19 from Section 5.1

24. The average daily temperature in January for cities along the Eastern seaboard of the United States and Canada generally decreases for cities farther north.
A city’s latitude in the Northern
Hemisphere is a measure of
how far north it is on the globe.

25. The average temperature, y, can be described by the equation where x is the latitude of the city.
Average Daily
Temperature(F)
Jacksonville, FL
30.3
52.4
Miami, FL
25.8
67.2
Atlanta, GA
33.8
41.0
Baltimore, MD
39.3
31.8
Boston, MA
42.3
28.6
Atlantic City, NJ
39.4
30.9
New York, NY
40.7
31.5
Portland, ME
43.7
20.8
Charlotte, NC
35.2
Norfolk, VA
36.9
39.1

26. The average temperature, y, can be described by the equation where x is the latitude of the city.
100 80 60 40 20
Temperature
Latitude

27. Which variable is the dependent
b. Which variable is the independent
variable?

29. Section 7.2 Applications of Linear Equations
Chapter 7:
Introduction to Relations and Functions
Section 7.2 Applications of Linear Equations
Let’s work Exercise #19 from Section 5.1

30. Section 7.2 Exercise #9 Chapter 7:
Introduction to Relations and Functions
Section 7.2 Exercise #9
Let’s work Exercise #19 from Section 5.1

31. This figure depicts a relationship between a person’s height, y (in inches), and the length of the person’s arm, x (measured in inches from shoulder to wrist).
100 90 80 70 60 50 40 30 20 10

33. The slope = 3.5
For each additional inch in length of a person’s arm, the person’s height increases by 3.5 inches.

35. Section 7.2 Exercise #11 Chapter 7:
Introduction to Relations and Functions
Section 7.2 Exercise #11
Let’s work Exercise #19 from Section 5.1

36. The cost to rent a car, y, for 1 day is $20 plus $0.25 per mile.
Write a linear equation to
compute the cost, y, of driving a car x miles for 1 day. or

37. The cost to rent a car, y, for 1 day is $20 plus $0.25 per mile.
b. Use the linear equation to
compute the cost of driving
258 miles in the rental car.

38. Section 7.3 Introduction to Relations
Chapter 7:
Introduction to Relations and Functions
Section 7.3 Introduction to Relations
Let’s work Exercise #19 from Section 5.1

39. Section 7.3 Exercise #7 Chapter 7:
Introduction to Relations and Functions
Section 7.3 Exercise #7
Let’s work Exercise #19 from Section 5.1

40. Write the relation as a set of ordered pairs.B C D E 1 2 3 4 5

41. Section 7.3 Exercise #11 Chapter 7:
Introduction to Relations and Functions
Section 7.3 Exercise #11
Let’s work Exercise #19 from Section 5.1

42. List the domain and range.B C D E 1 2 3 4 5

43. Section 7.3 Exercise #23 Chapter 7:
Introduction to Relations and Functions
Section 7.3 Exercise #23
Let’s work Exercise #19 from Section 5.1

44. Find the domain and range of the relations
Find the domain and range of the relations. Use interval notation where appropriate.

45. Section 7.3 Exercise #35 Chapter 7:
Introduction to Relations and Functions
Section 7.3 Exercise #35
Let’s work Exercise #19 from Section 5.1

46. (Source: Centers for Disease Control)
The percentage of male high school students, y, who participated in an
organized physical activity for
the year 1995 is approximated by
y = –12.64x For this
model, x represents the grade
level
(Source: Centers for Disease Control)

47. The percentage of male high school students, y, who participated in an
organized physical activity for
the year 1995 is approximated by
y = –12.64x For this
model, x represents the grade
level
Approximate the percentage
of males who participated in organized physical activity for grades 9, 10, 11, and 12, respectively.

48. Grade 9, x = 9:

49. Grade 10, x = 10:

50. Grade 11, x = 11:

51. Grade 12, x = 12:

52. The percentage of male high school students, y, who participated in an
organized physical activity for
the year 1995 is approximated by
y = –12.64x For this
model, x represents the grade
level
b. Can we use this model to predict seventh-grade participation? Explain your answer.