Multiplikation beider Seiten mit c :                         a = 0,5 c
                                            oder                         0,5 c = a

                                                                                          1
                                                                           0,5 c      a
Division beider Seiten durch a :                             ----- = ---
                                                                              a         a
                                                                                          1
                                                                   1
                                                                0,5 c        1
Division beider Seiten durch 0,5 :              -----   =  ---
                                                                0,5 a       0,5
                                                                  1
                                                                         c       1
Also:                                                                --- = ---
                                                                        a      0,5

            Sie sehen also, daß alle sechs Gleichungen dieselbe Aussage enthalten, nur sind sie immer ein wenig anders
            formuliert ; sie sind alle richtig .