Respuesta :

using substitution method
from the first equ
2x+y=-1
y= -1-2x --------(3)
put equ 3 into equ 2
3x -1-2x=6
3x-2x=6+1
x =7
put x+7 into equ 1
2(7) + y = -1
14 + Y =-1
y= -1-14
y=-15
so
x=7 and y=-15