It seems that your mathematical expression is a bit unclear due to formatting. Let's break it down and clarify:

You are mentioning:

• Two events $A$ and $B$.
• $P(A) P(AB) + P(BA) = \frac{3}{13}$
• $P(B) = \frac{12}{13}$
• $12P(AB) = \frac{1}{5}$

Let me try to address what this might represent:

1. $P(A) P(AB) + P(BA) = \frac{3}{13}$: This seems like a relation involving probabilities of joint events, but it's unclear what is meant by $P(A) P(AB)$ — do you mean the product of $P(A)$ and $P(AB)$? Or was it a typo?

2. $P(B) = \frac{12}{13}$:
   This is clear, and we know the probability of event $B$.

3. $12P(AB) = \frac{1}{5}$:
   Solving for $P(AB)$, we get: $P(AB) = \frac{1}{5 \times 12} = \frac{1}{60}$

Would you like me to help clarify these terms or proceed with solving the system? Let me know if you'd like a more specific answer or clarification of the setup.

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Here are some related questions:

1. How does the probability of the union of events $A$ and $B$ relate to the joint probability $P(AB)$?
2. How can you calculate $P(A \cup B)$ using $P(A)$, $P(B)$, and $P(AB)$?
3. What is the relationship between conditional probabilities like $P(A|B)$ and $P(B|A)$?
4. What does the formula $P(A \cap B) = P(A)P(B|A)$ signify?
5. How do you approach finding the value of $P(A)$ from joint probability data?

Tip: When working with probabilities, always check if events are independent or conditional, as it significantly impacts the formulas you use!