Respostas

2014-09-02T09:22:22-03:00
X + 4x = 15 - (-x -6)
5x = 15 + x + 6
5x - x = 15 + 6
4x = 21
x = 21/4
x é aproximadamente 5,2 
2014-09-02T09:23:10-03:00
X + 4x = 15 - ( - x - 6 )

x + 4x = 15 + x + 6

x + 4x - x = 15 + 6

4x = 21

x = 21/4