Thank you for the opportunity to help you with your question! Hope your day is going well!

This is a law of exponents problem. Let's use the identity

(a *b)^n=a^n * b^n

a=6

b=a

n=4

Therefore,

(6a)^4=6^4 *a^4=1296a^4

Or you could think about it one other way. When you are given a number, technically, it is raised to the 1st power. Well, when you have an exponent raised by another exponent, you multiply the exponents.

6^(1 *4) * a^(1 *4)

6^4a^4=1296a^4.

**Note, you can only do this when two numbers are being multiplied.

Please let me know if you need any clarification. I'm always happy to answer your questions.