Final answer:
Without additional context or clarification on the given values and setup, it is not possible to calculate Rax with the information provided. A free-body diagram and the use of equilibrium conditions for forces and moments are typically employed in such problems in physics.
Step-by-step explanation:
To calculate Rax, the reaction force at point A in the X direction, we would generally use the principles of static equilibrium for a rigid body. These state that for an object to be in equilibrium, the sum of all forces and the sum of all moments (or torques) about any point must be zero. Assuming we’re dealing with a static situation where the forces in question are applied horizontally at different points along a beam or similar structure supported at point A, you'd sum the forces acting in the X direction and set them equal to the reaction at A in the opposite direction.
However, the specific values provided in the question (200 lbs, 300 lbs, E: 3ft, D: -2ft, C: 2ft) do not directly relate to a typical statics problem and may be referring to distances from a pivot point or other lever arms in a system which would require more context to solve accurately. The equations provided in the reference text do not offer a clear solution to the question as asked either. The student may need to clarify the setup of the problem or provide additional information for a precise solution to be determined.
The strategy section and accompanying examples from the reference seem to suggest the use of the free-body diagram and equilibrium conditions, but without a specific example directly matching the given question, we cannot provide a definitive answer to calculate Rax.