Let's break down the problem based on the images you shared. This appears to be a mechanics problem related to forces and reactions in static structures. I'll go through each of the three questions one by one, starting with:

1. Determining the resultant forces and showing their point of application with respect to the force system:

   • In the first part of the diagram, you have three forces acting on the structure: 100N, 50N, and 3m in length.
   • The goal is to calculate the resultant force and where it applies along the system.

2. Finding the reactions at the supports of the structure below:

   • The second part of the diagram shows a structure with forces applied at angles and varying lengths. You need to determine the reactions at the supports of the structure under these loads.
   • This would involve resolving forces into components, considering equilibrium conditions, and solving for unknown reactions.

3. Finding the reactions on the structure at the bottom:

   • In the third part, a similar structure is provided, but with multiple distributed loads. The task is to calculate the reactions at the support, likely using force equilibrium equations.

Steps I will take:

• For each section, I will determine the sum of forces and moments acting on the structure, use equilibrium equations (ΣF = 0 and ΣM = 0), and calculate the reactions.

Would you like to proceed with the calculations for the first part, or would you prefer to dive into any specific question?