Respuesta :

Answer:      12.5

              y = 12.5x

Step-by-step explanation:

k = y/x

  = 50/4

  = 12.5

Notice that you could have used:    62.5/5 = 12.5      or     75/6 = 12.5

The equation is: y = kx

                           y = 12.5x