Respostas

2013-11-07T17:48:43-02:00
A)x+y=2                 2x+y=2                           x + y = 2
   x=2-y                 2(2-y)+y=2                      x + 2= 2
                             4 -2y +y=2                       x = 2 - 2
                              -y= -2 (-1)                        x = 0
                                 y = 2