Need help pls look at pic

Consider the function f(x)=-5x+3 what is f(-2)

If the sales price of a dvd is $20 and the markup is 34%, what is the cost of the dvd?

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