Respostas

2013-07-10T10:54:58-03:00
3x+2x-2x+4x==-1
7x=-1
x=-1/7
feito
2013-07-10T10:58:05-03:00
(3x + 2x - 1) + (-2x + 4x + 2)
(5x - 1) + (2x + 2)
eliminando os parênteses
7x + 1= 0
x = -1/7