For the question mark, we can insert a variable considering it is an unknown number.
[tex] \frac{3^6}{3^x} = 3^4 \\ \\ 3^{6-x} = 3^4 \ / \ use \ qotient \ rule \\ \\ 6 - x = 4 \ / \ cancel \ out \ 3 \\ \\ -x = 4 - 6 \ / \ subtract \ 6 \ from \ each \ side \\ \\ -x = -2 \ / \ simplify \\ \\ x = 2 \ / \ multiply \ each \ side \ by \ -1 \\ \\ Answer: \fbox {x = 2} [/tex]
