TITLE: Solving $8n^2=64 n\log(n)$
QUESTION [6 upvotes]: I am trying to solve:
$$8n^2=64 n\log(n)$$
I factored out $8n$ and was left with 
$$n = 8 \log n$$
but I do not know how to proceed from here, I checked the solution on Wolfram Alpha, and they were able to simplify it down to:

which is approximately:

how where they able to get to this point ?

REPLY [4 votes]: Your equation, after your initial simplification, simply write    
$$f(n) = n - 8 \log(n)$$
and you want $f(n)$ to be zero.   
By inspection (or better plotting the function), you notice that you have two solutions, one close to $1,$ the other close to $26$. I shall admit here that you do not know about Lambert function (from very far away, this is not a crime!!). Then the solutions will be obtained numerically.  
Since the function looks very well conditioned, Newton method is a very simple candidate for locating the roots as accurately as desired. Starting from a guess (let us name it $n_{old}$), the new estimate (let us name it $n_{new}$) is simply given by
$$n_{new} = n_{old} - f(n_{old}) / f'(n_{old})$$
and the process is repeated as long as the desired accuracy has not been reached.   
For illustration purposes, I shall start the iterations at $n_{old} = 1$. The successive iterates are then: $1.14286, 1.15529, 1.15537$.
For this last value, the function $f(n)$ is $4.88805\times10^{-6}$; this is quite accurate and only three iterations have been required.  
For the second solution, I shall start, on intent, quite far from the solution, say at $n_{old} = 15$. The successive iterates are then: $29.2809, 26.1639, 26.0935$.
For this last value, the function $f(n)$ is $1.00707\times10^{-5}$; this is quite accurate and only three iterations have been required.