Respostas

2014-06-12T13:30:24-03:00
3.(-12) x=72
3.-12x=72
-36x=72
x=72/36
x=2
1 4 1
2014-06-12T13:31:47-03:00
3.(-12).(-2) = 72
3.24 = 72
72 = 72
Logo:
X = -2