Two schools, A and B, took part in the math contest.
There are x people who set up a second school to participate in the competition, and one school is (25-x) people.
15×(25-x)+3= 13x
5- 15x+3= 13x
13x+ 15x=8
5 15x+3 15x=8
8 15x=8
x= 15
25- 15= 10 (person)
A: A school has 10 participants and B school has 15 participants.