Answer:
725= 125+ 12x (equation) 50$ (answer). x (variable)
Explanation:
725 = 125+ 12x
-125. -125
600 = 12x
12x = 600
divide 12, both sides
x = 50
So $50 dollars each month.
There's a 12 because there's 12 months in a year and it's asking for "each month"
x is the variable and it stands for how much money $ new members pay each month.