Respostas

2013-08-08T09:05:36-03:00
2(x+1) - (x-1)
2x + 2 - x +1 =0
x + 3 = 0 
x = -3
2013-08-08T09:52:04-03:00
2(x +1) — (x —1) = 0
2x +2 —x +1 =0
X + 3 =0
x= —3