Respostas

2014-05-26T21:55:23-03:00
X - y =17
2x+y=19
3x    = 36
x = 36 / 3
x = 12

x - y = 17
12 - y = 17
-y = 17 - 12
-y = 5    .(-1)
y = -5
1 5 1