I saw this analysis online but I have noticed contradicting values from this method of analysis. The drawing of the simply supported beam comes from the crane structure above. All we desire is the reaction forces as well as the external forces being experienced at each of the three points which represent the joints of part of the truss. The person has placed $150N$ acting in the middle of the beam creating a moment of $22500 Nmm$ and creating reactions of $75N$ at each support.
But I was told on one of my previous questions that this is innorect due to it being part of a truss and not just a beam. Is the correct way to split up the $150N$ into $50N$ acting upon points $P_1$ $P_2$ and $P_3$ which would result in a total moment of $30000 Nmm$ and reactions of $100N$ on the right end and $50N$ on the left end? Which method is correct in this situation?