Answer:
$15+x
x in dollars
Step-by-step explanation:
Subscription per month=$15
Cost of each downloaded song per month=$15 + 1
If x number of songs are downloaded in a month
The cost of downloading x songs= $15 + x
Where,
$15 = fixed cost ( subscription)
x= variable cost( each unit of songs downloaded)
If 20 songs are downloaded in a month.
The cost of downloading the 20 songs
=$15+$20
=$35
