A yoga studio offers membership that costs $48 per month.
Also accepts walk-ins, charging $3 per class.
If someone attends x classes in a month, the two options cost the same, that means:
$48=$3x
x=$48/$3
x=16
We can say that the walk-ins accept 16 classes for the same total amount.
Each option costs $48 if a person takes 16 classes.