Which set of ordered pairs represents a function?
{(-3,4), (-7,2), (-7,-4),(-9, -5)}
{(-2,4), (0,5),(-9,9),(-9,7)}
{(-4,-6), (-7, -5),(-4,-7), (1,1)}
{(5,-2), (-8,-6),(4, -2), (-6,3)}​

Respuesta :

Answer:

The correct answer is D.

Step-by-step explanation:

A function is when an input value has only one output value.

It cannot be A, because -7 produces both 2 and -4.

It cannot be B, because -9 produces both 9 and 7.

It cannot be C, because -4 produces both -6 and -7.

Therefore, it has to be D.