Question

X+y=0
X- y=8

Ajudaaaa!

Answer 1

sistema 

2x = 8
x = 4

Achando o y :

x + y = 0
4 + y = 0
y = 0 - 4
y = -4

Answer 2

X + Y = 0
X - Y = 8

X = 8 + Y
X + Y + Y = 0
2Y = 0 - 8
2Y = -8
Y = -8/2
Y = -4
X = 4 + 0
X = 4