Respostas

2014-08-03T21:11:32-03:00
 x + 3x = -600
4x = -600
x = -600/4
x = -150
R = -150 
2014-08-03T23:25:34-03:00
X+3x=-600
4x=-600
x=-600/4
x=-150
(x E Z)