Music yearly membership
We want to know what part of the total cost of vinyl albums is due to the cost of the membership.
We know there are two parts of the price costumers have to pay:
1. yearly membership: Y
2. vinyls: X
We can find the cost due to the vinyls multiplying the cost of each one by the number of vinyls.
For 4 vinyls, the cost due to it is 4X
For 7, it is 7X
For 9, it is 9X
This means that the total cost of vinyl albums is
cost due to vinyls + yearly membership = total cost
For 4 vinyls, the total cost is $35.00, then
4X + Y = $35.00
For 7, the total cost is $57.50, then
7X + Y = $57.50
For 9, the total cost is $72.50, then
9X + Y = $72.50
Using the first two equations:
4X + Y = $35.00
7X + Y = $57.50
we are going to find Y.
Clearing X from the first equation:
We replace this value of X in the second equation:
Then, the yearly membership cost is $5
Answer. A: $5.00