Question 1004235
Why, and not showing any y variable, how?  You should want to simplify your expression.


{{{81^(log(9,8x))}}}


{{{(9^2)^log(9,(8x))}}}


The site's rendering might not give a good display, but continuing,...


{{{9^(2*log(9,(8x)))}}}


{{{9^(log(9,(8x)^2))}}}
Next, because exponential function and log function are inverses, their composition will be their input:


{{{(8x)^2}}}


{{{highlight(64x^2)}}}