7             4                                 7 |5      4|2                             7*5 - 4*2

13-5 ------ - 1 --------- = (13-5-1)+(-------- - -------) = (13-5-1)+(------------------) =

           12            15                              12        15                                      60

                          35-8                    27

= (13-5-1)+(-------------) = 7 -------------

                            60                     60

Verified answer

13-67/12-19/15=(2340-1005-228)/(12*15)=1107/180