Answer:
5 months
Step-by-step explanation:
Set up an inequality, using x to represent months.
(The 35 and 40 represent the cost per month, and you add the 100 and 75 just once because it's a one-time fee and not monthly)
35x + 100 < 40x + 75
Now solve for x.
5x > 25
x > 5
This means that the membership will be less expensive after 5 months.