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.
