The expression in the image you provided is:

$a^5 \cdot a^4 = a^?$

Here, we see a product of two powers of the same base $a$. According to the product of powers property, when multiplying exponents with the same base, you add the exponents:

$a^m \cdot a^n = a^{m+n}$

In this case:

$a^5 \cdot a^4 = a^{5+4} = a^9$

Thus, the result is:

$a^9$

Would you like more details, or do you have any other questions?

Here are 5 related questions to deepen your understanding:

1. What is the product of $a^2 \cdot a^7$?
2. How do you handle division with exponents, such as $a^8 \div a^3$?
3. What is the result of $(a^3)^4$?
4. How do you simplify expressions like $a^5 \cdot b^5$ where the bases are different?
5. How do you deal with negative exponents in multiplication, such as $a^{-3} \cdot a^2$?

Tip: When multiplying powers with the same base, always remember to add the exponents.