Question

x-y= -1
2x+y = 4 ?  me  ajudem 

Answer 1

{ x - y = -1
{2x+y = 4
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
3x ////= 3 ---> x = 1
x -y = -1 --> -y = -1 - x ---. -y = -1-1--> -y = -2 --> y = 2

S= {1 ; 2}