55 SO
45
40
35
30
25
(40, 36)
.
Total Cost (in dollars)
On average, Susan downloads 60 songs per month. An
online music vendor sells package prices for songs that
Online Music Purchases
can be downloaded onto personal digital devices. The
graph below shows the package prices for the most
popular promotions. Susan wants to know if she
should buy her music from this company or pay a flat
(20,18)
fee of $58.00 per month offered by another company.
20
15
Which is the better buy?
Solo)
이 ·
a. Find the constant of proportionality for this
situation.
Number of Songs Purchased
b. Write an equation to represent the relationship.
C. Use your equation to find the answer to Susan's question above. Justify your answer with mathematical
evidence and a written explanation.
(12, 10.8
.
10
15,4,5)
0
40
45
SO
55
35
30
15
25
S
10
20
0
S.33
Representing Proportional Relationships with Equations
Lesson 8:
EUREKA
MATH
2016 Great Minds. eureka-math. org