Solution: If each person needs to pay X yuan, then after adding 2 people, each person needs to pay 12(x-3) yuan. According to the meaning of the question:
10x= 12(x-3)
If there are no brackets, you get 10x= 12x-36.
If you move this item, you will get 10x- 12x=-36.
Combine similar items and get -2x=-36.
The coefficient is 1 and x= 18.
A: Everyone should pay 18 yuan.