Final answer:
The question relates to solving an inequality in Mathematics, possibly in the context of Physics and special relativity, where variables like v and u' could pertain to velocities as fractions of the speed of light (c).
Step-by-step explanation:
The core subject matter of the question appears to be Mathematics, specifically related to the solving of inequalities or equations. The text provided offers a mixture of what seems like related variables (v, u') and constants (c), normally associated with physics and special relativity, indicating that the context might be a physics problem rather than just mathematics. However, the initial comparison 57/5 & lt; -v +23/5 v is an inequality, which is a mathematical concept.
From the given information with notations as 'c' (possibly representing the speed of light), and the use of variables like 'u' and 'u'', it is hinting towards topics covered in a Physics class, perhaps at a level consistent with Advanced Placement (AP) or college introductory physics courses, where relative velocity and special relativity are discussed.
Without a clear question or specific context, it is difficult to provide an accurate solution. Nonetheless, if the aim is to solve for a variable, one needs to apply the appropriate formulas and algebraic manipulation to isolate and solve for the unknown.