Respuesta :

Answer:

All are functions

Step-by-step explanation:

A.  y = x + 9  A graph of a line. There are no x-values that are the same on the graph. The graph passes the vertical line test.

B.    x + y = 9

       y = -x + 9   A graph of a line.  There are no x values that are the same number on the graph.  The graph passes the vertical line test

C.  x + 3 = y²

   [tex]\sqrt{x + 3} = y[/tex]  The graph passes the vertical line test. On the graph, there are no x-values that are the same number.

D.   y = x² - 3   The graph is a parabola. The graph passes the vertical line test (there are no x- values are the same number on the graph).