Respostas

2014-02-08T14:16:29-02:00
4z-(2z-3)=-(2z+1)
4z - 2z + 3 = -2z - 1
2z + 3 = -2z - 1 
4z = -4
z = -1
2014-02-08T14:24:40-02:00
4z-(2z-3)=-(2z+1)
4z-2z+3=-2z-1
2z+3=-2z-1
4z=-4
z=-1