Which set of ordered pairs represents a function? {(-3,7), (7,-3), (-7,6), (-7, -1)}
{(7, -3), (-3,-9), (-3,-8), (8,1)}
{(8,-9), (4,-8), (-4,0), (-2,-8)}
{(-2,8), (-3,-3), (1, –4), (1,9)}

Afitness center has 2 membership plans one has a low dollar sign up fee of 15 dollars and costs 38 dollars per month to join. a second plan has a higher sign up fee of 78 dollars but a lower monthly fee of 31 dollars for what number of days of the month is the coat the same