(3/13 + 4/7) * 91=73
3/4*(5/9-2/3)=-0,08333
3/4*(5/9-2/3)=3/4*(5/9-6/9)=3/4*(-1/9)=-1/12
(3/13+4/7)*91=(21/91+52/91)*91=73/91*91=73/91*91/1=73/1*1/1=73
(3/13 + 4/7) * 91=73
3/4*(5/9-2/3)=-0,08333
3/4*(5/9-2/3)=3/4*(5/9-6/9)=3/4*(-1/9)=-1/12
(3/13+4/7)*91=(21/91+52/91)*91=73/91*91=73/91*91/1=73/1*1/1=73