In a class of 23 student the girls were 7 more than the boys how many boys were in the class

x=# of boys

x+7=# of girls

x+x+7=25

2x+7=25

2x=25-7

2x=18

x=18/2

x=9 boys

x+7=16 girls

If you don't understand variables use trial and error.

Boys Girls

1 8

2 9

3 10

4 11

5 12

6 13

7 14

8 15

9 16 9+16=25 students

You could start this way ...

Boys Girls

12 13

11 14

10 15

9 16 16 is 7 more than 9