Respuesta :

 x+3y=-5

4x-y= 6

--------------------

-4(x+3y=-5)

  4x-y=6

-----------------------

-4x-12y=20

4x-y=6                        the 4 y's will eliminate each other

--------------

0 -13y=26

-13y=26

y=26/-13

y=-2