Hallo,
s²-2s-3 =(s+1)(s-3)
->
3s+7 /((s+1)(s-3)) =A/ s+1) +B/(s-3) ->Partialbruchzerlegung
3s+7 =A/ (s-3) +B/(s+1)
z.B. Einsetzmethode:
s1= -1 : 4= A (-4) -------->A=-1
s2= 3 : 16=4B ----->B=4
-->
3s+7 =(-1)/ (s-3) +4/(s+1)
y(t)= \( 4 e^{3 t}-e^{-t} \)