Help me please with my geometry

Molly shared a spool of ribbon with 12 people. each person received 3 feet of ribbon. which equation can she use to find r, the number of feet of ribbon that her spool originally had?

Sample response: if the graph passes the horizontaline test, then the function is one to one. functions that are one to one have inverses that a therefore, the inverse is a hinction compare your response to the sample response above. what did you include in your explanation? a reference to the horizontal-line test d a statement that the function is one-to-one the conclusion that the inverse is a function done

Math question.. plz me .. best answer all