a college student yakes a summer job selling newspaper subscriptions door-to-door. She is paid $36 for a four-hour shift. She also earns $7 for each subscription sold.
a) create a function f (x) for the amount she earns on a shift during which she sells x subscriptions.
b) use the function f(x) to determine how much she earns on a shift during which she sells 12 subscriptions