Which of the sets of ordered pairs represents a function?

a = {(2, −2), (5, −5), (−2, 2), (−5, 5)}
b = {(4, 2), (4, −2), (9, 3), (9, −3)}

Acable car begins its trip by moving up a hill. as it moves up, it gains elevation at a constant rate of 50 feet/minute until it reaches the peak at 2,000 feet. then, as the car moves down to the hill’s base, its elevation drops at the same rate.

Neveah and clint are baking muffins for the bake sale. they need to bake 30 muffins for their display case. clint has baked 4 so far, and neveah has baked 7. how many muffins (m) do they have left to bake? show your work!

Explain how you can use the associative property to evaluate (7x50)x4.