Respostas

2014-07-20T12:05:57-03:00
X+3y=30
2x+3y=60

x=30-3y

2x+3y=60
2*(30-3y)+3y=60
60-6y+3y=60
-3y=60-60
-3y=0
y=0/-3
y=-0

x=30-3y
x=30-3*(-0)
x=30+0
x=30