Respostas

2014-05-20T17:39:30-03:00
X+y = 3 +
2x-y=3
3x=6
X=2 y=1

B) 3x+2y=12 - 3x+2y=12 -
2x+y=7 x2 4x+2y=14
-x=-2 x=2