Respostas

2014-02-10T12:09:44-02:00
7x+y=50
7x+1=50
7x=49
x=49/7
x=7
1 5 1
2014-02-10T12:55:20-02:00
7x+y=50
7x+.(1)=50
7x+1=50
7x=50-1
7x=49
x=49/7 ou   x=7