Question

Kim borrowed $400 from her parents to purchase a new cell phone. The table represents Kim's repayment schedule. Which inequality states the domain of the relation?

Answer 1

The domain tells you about the independent variable, number of payments made. So the inequality should be

smallest number of payments made ≤ variable representing payments ≤ largest number of payments made.

The smallest number of payments is 0 and the largest is 8, so you'll have
\[0 ≤ variable ≤ 8\]