Laplace transformation step by step

Questions
,
1

I’d like to know how or where obtain a step by step transform.
One example could be: 1/(1+3s)^n

Thank you in advance and excuse me for my ignorance

2

In[3]:= LaplaceTransform[(1 + 3 t)^-n, t, s]

Out[3]= 1/3 E^(s/3) ExpIntegralE[n, s/3]

In[4]:= Integrate[(1 + 3 t)^-n Exp[-s t], {t, 0, \[Infinity]}]

Out[4]= ConditionalExpression[1/3 E^(s/3) ExpIntegralE[n, s/3], 
 Re[s] > 0 || (Re[s] >= 0 && Re[n] > 1)]
3

Is this a solution step by step? It doesn’t seem to me but I may be wrong. I’d like to obtain the exact procedure to calculate this transform on paper.

4

Quite possibly W|A simply does not support Show Steps for the Laplace transform.