Heyo. Let's go ahead and set this problem up
It should look like this
12x + 125 = 725
The variables can be another letter, doesn't matter.
12 will stand for the months in a year
x is the amount paid per month
125 is the registration free
725 is the one year membership total
Subtract both sides by 125 to get:
12x = 600
Divide both sides by 12 to get:
x=50
That being said, each month, a new member will pay $50.
