Respostas

2013-11-16T19:16:46-02:00
a) -12+8x-16+16-16+6x=0
                                14x-28=0
                                 14x=28            x=2

b)8+12-x-6x-8+2=0
                                    -7x+14=0
                                     -7x=-14             x=2

c)8+12-x-6x-8+2=-7
                                              -7x+14=-7
                                              -7x=-7-14
                                              -7x=-21       x=3

d)
8x+18-4x=26
                                            4x+18=26
                                            4x=26-18
                                            4x=8      x=2