Which of the following relations is a function?
{(5, –7), (4, 6), (–3, 8), (5, 9)}
{(8, –4), (–4, 8), (–4, –8), (–8, 4)}
{(2, 3), (–2, 3), (3, 2), (–3, –2)}
{(9, –1), (–1, 9), (9, 2), (2, –1)}

What value of x is in the solution set of 4x – 12 s 16 + 8x?

Askate shop rents roller skates as shown on the table below. which graph and function models this situation?

Ms.ortiz sells tomatoes wholesale. the function p(x)=-80x^2+320x-10, graphed below, indicates how much profit she makes on a load of tomatoes if she makes on a load of tomatoes if she sells them for 4-x dollars per kilogram. what should ms.ortiz charge per kilogram of tomatoes to make on a load of tomatoes?