Respostas

2014-02-19T17:59:33-03:00
X+2y=10
3×=10
×=10/3 3×+3y=6
6×=6
×=6/6=1
2014-02-19T20:00:45-03:00
X+2y=10    isolando o x     x=10-2y
3x+3y=6     substiruindo nessa  
3(10-2y)+3y =6
 30 -6y+3y =6
-3y = 6 -30
-3y = -24
y= -24/-3
y=8

x=10-2y
x= 10 - 2(8)
x=10 -16
x=-6
S={-6,8}