I see the math problems from the image. The problems seem to be about logarithmic expressions. Let me break them down for you:

1. Problem A:
   $3 \log_5 25 \cdot 5 \log_3 81 = \, ?$ To solve this, we first simplify the logarithmic terms:

   • $\log_5 25 = 2$ because $5^2 = 25$.
   • $\log_3 81 = 4$ because $3^4 = 81$.

   Thus, the expression becomes: $3 \cdot 2 \cdot 5 \cdot 4 = 120.$

2. Problem B:
   $\log_3 \left( 5 \log_5 125 \right) = \, ?$ First, simplify $\log_5 125$:

   • $\log_5 125 = 3$ because $5^3 = 125$.

   So the expression becomes: $\log_3 (5 \cdot 3) = \log_3 15.$ The exact value of $\log_3 15$ cannot be simplified further without a calculator, but it would be a decimal value close to $2.46$.

3. Problem C:
   $2 \log_3 72 - 2 \log_3 3 + 2 \log_3 4 = \, ?$ Using the properties of logarithms: $2 \log_3 \left( \frac{72 \cdot 4}{3} \right) = 2 \log_3 \left( \frac{288}{3} \right) = 2 \log_3 96.$ The exact value of $\log_3 96$ is also a decimal, approximately $3.35$. So: $2 \cdot 3.35 = 6.7.$

Let me know if you'd like more details or further clarifications!

Here are 5 related questions to further explore the concept:

1. How do you apply the change of base formula for logarithms?
2. Can logarithmic identities help simplify expressions like $\log_3 72 + \log_3 4$?
3. What is the difference between natural logarithms and common logarithms?
4. How can logarithmic functions be used to solve exponential equations?
5. Can you find the derivative of a logarithmic function like $\log_3 x$?

Tip: Always remember to use properties of logarithms, such as the product rule and the power rule, to simplify complex logarithmic expressions.