Respostas

2013-07-02T12:44:14-03:00

O segredo é isolar um deles:

*x/4=y/6

x=4y/6

x=2y/3

*x+y=15

 2y/3+y=15

2y+3y=45

5y=45

y=9

*x+y=15

x+9=15

x=6

2 5 2
2013-07-02T12:46:09-03:00

x/4=y/6

x=4y/6

x=2y/3

______________________________________

x+y=15

2y/3+y=15

2y+3y=45

5y=45

y=9

_______________________________________

x+y=15

x+9=15

x=6

1 5 1