Name: ____________________________
Period: __________
2.2.3 HW
2-71. Sometimes the quickest and easiest two points to use to graph a line that is not in slopeintercept form are the x- and y-intercepts. Determine the x- and y-intercepts for the two lines
below and then use them to graph each line. Write the coordinates of the x- and y-intercepts on
your graph. (Use on-line textbook for Homework Help ✎)
a. x − 2y = 4
x - Intercept
y - Intercept
b. 3x + 6y = 24
x – Intercept
y - Intercept
2-72. Solve each of the following equations. (Use on-line textbook for Homework Help ✎)
a. 2x + 8 = 3x − 4
b. 1.5w + 3 = 3 + 2w
c. 48 + 8x + 23 = 7
d. 6x − 21 = 5x + 17 + x
2-73. A consumer magazine collected the following data for
the fuel efficiency of cars (miles per gallon) compared to
weight (thousands of pounds). (Use on-line textbook
for Homework Help ✎)
e = 49 − 8.4w
w is the weight (1000s of pounds)
and e is the fuel efficiency (mpg).
a. What does the −8.4 in the equation represent? What are the units on this number?
b. What does the 49 in the equation represent? What are its units?
c. Describe the association between fuel efficiency and weight.
d. Cheetah Motors has come out with a super lightweight sports utility vehicle (SUV) that
weighs only 2800 pounds. What does the model predict the fuel efficiency will be?
2-74. Each part below represents a different situation. For each situation, determine the pattern
of growth and the number of tiles in Figure 0 or the y-intercept. (Use on-line textbook
for Homework Help ✎)
a.
c. y = 3x – 14
d.
e. Which situation above is growing (increasing) at the fastest rate?
b.
2-75. Paula found a partially completed table that her friend Donna was using to determine how
fast water evaporated from a bucket during the summer. Every other day she measured the
height of the water remaining in the bucket in centimeters.
(Use on-line textbook for Homework Help ✎)
Days (x)
0
2
4
Height cm (y)
30
27
24
6
8
a. Review the Math Notes box in Lesson 1.1.2. Is this a proportional situation? If it is
proportional, is it increasing or decreasing? If it is not proportional, explain why not.
b. Complete the table.
c. For this table, what is the rate of change, including the units? What is the unit rate of
change?
d. Write an equation to represent the height of the water after any number of days.