Answer:
The dependent variable is the amount of hairballs tallied up at the end of each week.
The independent variable is the brushing of the cats hair. because the person controls that.
The constants are the amount of food, feeding time, playing amount, and the amount of weeks.
Step-by-step explanation:
The amount of hairballs tallied up is the dependent variable because it is influenced by the independent variable which is brushing the cats hair. The person brushes their cats hair in hopes to reduce the amount of hairballs they find in the week.