(5 2/13 - 7 1/39 ) : 73/78
(5 2/13 - 7 1/39 ) : 73/78=(67/13 - 274/39 ) : 73/78=(201/13 - 274/39 ) : 73/78=- 73/39*78/73=
=-78/39=-2
1)5 2/13-7 1/39 =67/13-274/39= -(274/39-67/13)= -(274/39-201/39)= -73/39 = -1 34/39
2) -73/39:73/78= -73/39*78/73= -2