(3/(х+4)+6х/(х^2+х-12)-1/(х-3)): (8х-13)/(х^2-16)=(3/(х+4)+6х/((х+4)(х-3))-1/(х-3)): (8х-13)/(х^2-16)=
(3х-9+6х-х-4)(х-4)(х+4)/((8х-13)(х+4)(х-3))=(х-4)/(х-3)=1-1/(х-3)
(3/(х+4)+6х/(х^2+х-12)-1/(х-3)): (8х-13)/(х^2-16)=(3/(х+4)+6х/((х+4)(х-3))-1/(х-3)): (8х-13)/(х^2-16)=
(3х-9+6х-х-4)(х-4)(х+4)/((8х-13)(х+4)(х-3))=(х-4)/(х-3)=1-1/(х-3)