Answer
See below
Work Step by Step
We are given that $F(s)=\frac{50e^{-3s}}{(s+1)^2(s^2+4)}$
Now,$f(t)= L^{-1}[\frac{50e^{-3s}}{(s+1)^2(s^2+4)}]\\
=L^{-1}[\frac{2se^{-3s}}{s+1}+\frac{10e^{-3s}}{(s+1)^2}-\frac{25se^{-3s}}{s^2+4}]\\
=5u_3(t)[se^{-(t-3)}+2e^{-(t-3)}(t-3)-5\cos 2(t-3)]$