Question

Determine which set of ordered pairs is a function.

A. {(–1, 3), (1, 4), (–1, 5)}
B. {(5, 3), (–6, 3), (–2, 4)}
C. {(0.5, 1.6), (1, 1.75), (1.5, 2.3), (0.5, 3.6)}
D. {(1, 2), (–5, 4), (3, 6), (–5, 2)}

Answer 1

It's going to be the set of ordered pairs which don't have any two pairs with the same LEFT-coordinate but different RIGHT-coordinates.
For instance, the set in A is not a function, because it has
(-1,3) and (-1,5)
same left-coordinate, different right-coordinates...

Answer 2

OOOOOH

Answer 3

Which is your answer?