# Homework Help: Solving logaritm equation

1. Jan 25, 2012

### MattiasMath

I've run into a dead end trying to solve this equation and I was hoping that someone here might be able to point me in the right direction!

1. The problem statement, all variables and given/known data
xlgx = x4/1000

2. Relevant equations
-

3. The attempt at a solution
xlgx = x4/1000
lg(xlgx) = lg(x4/1000)
(lgx)2 = lg(x4) - lg(1000)
(lgx)2 = 4lgx - 3

Now after this point I'm not sure what to do. I tried:
3 = 4lgx - (lgx)2
3 = lgx * (4 - lgx)

But that doesn't seem to lead me anywhere. Any help would be much appreciated!

Last edited: Jan 25, 2012
2. Jan 25, 2012

### issacnewton

you have a quadratic equation in $\log(x)$

let $t=\log(x)$ and solve quadratic equation in t

3. Jan 25, 2012

### MattiasMath

Of course, obviously!

Thanks a lot for your help, much appreciated.