Math application problem 1: There are three times as many boys as girls in the classroom. After going out with 18 boys, the number of boys and girls in the classroom is the same. How many boys and girls are there?
1. solution: for x girls, there are 3X boys.
3X- 18=X
The solution is x = 9.
So the result is 27 boys and 9 girls.
2. solution: there are x ships.
15X+9= 18(X- 1)
The solution is X=9.
So there are nine boats.