Respostas

2014-02-02T22:01:09-02:00
A)3x-7=0
3x=7
x=7/3

b)2x-4=0
2x=4
x=4/2
x=2

c)5x=5x

d)2x+4=2x-2
2x-2x= -2-4
0x=-6
x=0