Respuesta :

Answer:

x+y=-8

Step-by-step explanation:

y-x=4

x=3y

y-3y=4

x=3y

-2y=4

x=3y

y=4/(-2)

x=3y

y=-2

x=3*(-2)

x=-6, y=-2 then

x+y=-6-2=-8