Respostas

2014-08-20T17:27:15-03:00
3X+{2Y-[5X-(Y+X)]}
3X+{2Y-[5X-Y-X]}
3X+{2Y-[4X-Y}
3X+{2Y-4X+Y}
3X+{3Y-4X}
3X+3Y-4X
-X+3Y