Respuesta :

x=3y+5 → x-3y=5  ..(1)
                x-4y=3  ..(2)

→The second  equation we must multiplication by (-1)

→x-3y=5
→-x+4y=-3

x's is lost..

4y-3y=5-3
y=2

x-3.2=5
x=5+6=11