$5-22.$ Determine reactions at A and B $.$

Step $1$: Make following replacements:

Replace roller at A with force. Since section of the beam is at $30$ to horizontal axis and force resisted by the roller is perpendicular to the beam, it is at $30$ to the vertical axis.

Replace pin at B with set of horizontal and vertical forces

Replace distributed load with equivalent concentrated load of $4m*3k\frac{N}{m}=12$ kN $,$ located at $4\frac{m}{2}=2m$ to the left of B

Draw free body diagram