Respostas

2014-08-31T13:50:31-03:00
3.x -23=55
3x=55+23
3x=78
x=78/3
x=26

Espero ter ajudado :D
2014-08-31T13:59:28-03:00

55+23=78/3=26                                                                                                                     


26 com certeza