Question

$\left \{ {2x + y = 0} \atop {x + y = 0}} \right.$

me ajudem a resolver, preciso muito!!

Answer 1

2x+y=0
x+y=0(×-1)

2x+y=0
-x -y=0
_____+
x=0

x+y=0
0+y=0
y=0