A middle school has a speech club with a total of 18 students. The ratio of girls to boys is 4:5. How many girls are in the speech club? How many boys are in the speech club? Justify your answers. (using linear equations)

The ratio is 4:5

so girls=4x

and boys=5x

(because you don't know how many boys or girls there are)

then the equation would be

4x+5x=18

9x=18

so x=2

then 2 times 4 which equals 8

and 2 times 5 which equals 10

so there are 8 girls and 10 boys