Respuesta :
Answer:
90 students are in the class
Step-by-step explanation:
So basically, you need to make this ration fraction equation:
[tex]\frac{1}{3} \\\\[/tex] - [tex]\frac{1}{9} \\[/tex] = 20 .
you would come up with 2/9 is 20.
Times it by both sides and you will get 180=2x.
Note this x is added so you will get a variable and not get confused.
Then, your answer would become x=90.