It seems like the symbols in your question didn’t render properly. Let’s break it down and try to reconstruct the problem.

If we assume the question involves sets $A$ and $B$, with various set operations, it could look something like this:

Given:

• $n(A) = 58$ (the number of elements in set $A$)
• $n(B') = 25$ (the number of elements in the complement of set $B$, i.e., elements not in $B$)
• $n(A \cap B) = 7$ (the number of elements common to both sets $A$ and $B$)

You are likely looking to calculate $n(A \cup B)$ or perhaps other quantities involving the union or intersection of sets.

Formula:

To calculate the number of elements in the union of two sets, $A \cup B$, we can use the following equation:

$n(A \cup B) = n(A) + n(B) - n(A \cap B)$

Since you are given $n(B') = 25$, we can find $n(B)$ using:

$n(B) = n(U) - n(B')$

Where $n(U)$ is the total number of elements in the universal set. If you know $n(U)$, we can proceed with the calculation.

Would you be able to clarify or provide more details about the universal set, or any missing information? I’ll also guide you through solving once we have all necessary data.

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Expansion Questions:

1. What is the total number of elements in the universal set $U$?
2. Do we have additional details on the relation between sets $A$ and $B$?
3. Are there any restrictions or special properties for sets $A$ and $B$?
4. Is the problem asking for other quantities beyond $n(A \cup B)$?
5. Are you familiar with Venn diagrams for solving such set problems?

Tip: Always confirm whether you're dealing with finite or infinite sets when applying these formulas.