Решите уравнения, с-12=0 х:108=1 b*15=0

 с-12=0  с=0+12 с=12     х:108=1 х=1*108 х=108     b*15=0 b=0*15 b=0        

с-12=0                         х:108=1                              b*15=0 с=12+0                        х=108*1                              b=15:0 с=12                             х=108                                  b=0 12-12=0                      108:108=1                          0*15=0 0=0                               1=1                                       0=0