Express as a single logarithm: 18log_4 radical 4x-1-log_4 8/x + log_4 8?

18log_4 √(4x-1) can be rewritten as log_4 (√(4x-1))^18 = log_4 (4x-1)^9

Then when you subtract log_4 8/x, you can combine these into one radical as a quotient of the things inside the logs.

That will look like:

log_4 [(4x-1)^9 / (8/x)] = log_4 [x(4x-1)^9 / 8]

Lastly, adding log_4 8 means you multiply 8 to the stuff inside the other log. But since what we have so far has a denominator of 8, the 8s will cancel.

log_4 {[x(4x-1)^9 / 8] * 8} = log_4 [x(4x-1)^9]