Respostas

2014-07-11T12:16:18-03:00
3x + 9x : -7 -5
 12x: -12
x: -12/ 12
x: -1
2014-07-11T12:18:03-03:00
3x + 5 = -9x -7
3x + 9x = -7 -5
12x = -12
x = -12/12
x = -1