Question

Representing Proportional Relationships with Equations

Answer 1

Answer:

a. 0.9

b. y=0.9x, where y is the cost and x is the amount of songs.

c. She should use the package price from the online music vendor (the first option)

Step-by-step explanation:

a.

The constant of proportionality is k in y=kx. Take a point form the graph ( lets say (5,4.5) ) and sub it in:

y=kx

4.5=5k

k=0.9

b.

The equation of a line is y=kx when it passes though the origin (which this one does). We know the value of k, so our equation is y=0.9x, where y is the cost and x is the amount of songs.

c.

Susan downloads 60 songs monthly. We're being asked if it would be cheaper to use the service where you play $58 total, or $0.90 per song. So for the package price, let's figure out the total cost (y) for 60 songs (x=60):

y=0.9x

y=0.9(60)=$54

So it would be cheaper to use the package price from the online music vendor.