Use the vertical line test to determine if the relation {(–6, –2), (–2, 6), (0, 3), (3, 5)} is a function

Our goal is to collect email addresses from 60% of customers who purchase a product." so that means if i talk to 95 customers, i need to persuade to provide an email address?

Ineed if you could explain and give me the answer you! this needs done

Witch represents the inverse of the function f(x)=1/4x-12