Zoe is comparing two local yoga programs. yoga-weigh charges $90 a month and registration fee of $35. essence of yoga charges $80 per month with a $75 registration fee. after how many months will the schools charge the same amount?
show your work for whoever is answering this

Let us first note down all the information's that are provided in the question in a sytematic manner and then proceed to solving this problem.
Registration fees charged by Yoga-Weigh = $35
Monthly charges of Yoga-Weigh = $90
Registration fees charged by Essence of Yoga = $75
Monthly fees charged by Essence of Yoga = $80
Let us assume that after x months the charges of both the schools will be same.
Then we can write the equation as
35 + 90x = 75 + 80x
90x - 80x = 75 - 35
10x = 40
x = 40/10
  = 4
So after 4 months the charges of Yoda-Weigh and Essence of Yoga will become the same. I hope the procedure for doing this problem is clear to you.

What do you mean by that?