Equation

PLEASE, /sci/, I need your help!

Here's the equation:
8*3^{x+\sqrt{x}}=9^x-9^{\sqrt{x}+1}

I can't solve it. I tried many things, but I fail every single time. I know the answer (which Mathematica/Wolfram|Alpha gave me) but that's not what I want.
What I need is a step-by-step solution or some good hints.

I'll be very glad if you help me out.
Thanks in advance.

>>8
Hmm.. That's something I don't understand yet. How did you get the second line?
And is it actually possible to logarithm a negative number?