Answer:
The expression for the total cost is x = 19.99 + 0.99n .
Explanation:
Let us assume that the total cost be x.
As given
Sophia pays $19.99 membership fee for an online music store.
If sophia purchases n songs for $0.99 each .
Than the expression becomes
Total cost = Membership fee + Cost of n songs
x = 19.99 + 0.99n
Here n represented the number of songs.