Respostas

2013-08-08T22:31:08-03:00
X + 15 = -2x + 9
15 - 9 = -2x - x
4 = -3x
x = -3/4
1 2 1
2013-08-08T22:31:26-03:00
X + 15 = -2x + 9
x + 2x = 9 - 15
3x = -6
x = -6/3 x = -2
1 5 1