Respostas

2013-10-03T11:03:09-03:00
7z - 1 = 5z + 13
7z - 5z = 13 + 1
2z = 14
z = 14 / 2
z = 7
2013-10-03T11:07:14-03:00
7z-1=5z+13
7z-5z=1+13
2z=14
14/2=z
7=z