A uniform beam of 6 m length and 300 n weight supports a 400 n load as shown below. Determine the tension in the supporting wire and the force exerted by the pivot on the beam.

Since you didn't post a figure, you should describe the arrangement as depicted in the missing figure. But without seeing the figure I would suggest that you consuider the moments operating about the point were the beam is connected to the wall - if it's a pivot point then at that point \small {\sum} \normalsize M= 0, so the sum of moments due to the beam's weight at it's center of mass, the load, and the tension in the supporting cable must all cancel out. Once you have determined the tension in the cable finding the reaction forces is simply a matter of setting \small \sum \normalsize F_x =0 and \small \sum \normalsize F_y = 0.