Respuesta :

-2x-y=3    ...(1)
x+2y=4    ...(2)
multiply (2) by 2 and add to (1)
-2x-y+2x+4y=3+8
3y=11
y=11/3
from (2)
x=4-2y=4-2(11/3)
or x=4-(22/3)
=(12-22)/3=-10/3