I want to find the laplace inverse of

$s}^{-\frac{3}{2}$

the steps given in the solution manual are as follows:

$\frac{2}{\sqrt{\pi}}\frac{\sqrt{\pi}}{2{s}^{\frac{3}{2}}}=2\sqrt{\frac{t}{\pi}}$

I know the first part$\frac{2}{\sqrt{\pi}}$ is obtained using the gamma function $\mathrm{\Gamma}\left(\frac{3}{2}\right)$ , but not quite sure how the rest is obtained.

the steps given in the solution manual are as follows:

I know the first part