1. Help me, please! Simple log solve for X

Hi. I'm a n00b and need to refresh my memory. I've not done this in a very long time.

How do I solve for X?

30 = 10lg(20/x)

Please, show me the basic steps. Thank you.

2. Originally Posted by mathsgre
Hi. I'm a n00b and need to refresh my memory. I've not done this in a very long time.

How do I solve for X?

30 = 10lg(20/x)

Please, show me the basic steps. Thank you.
The "inverse" of a logarithem is an exponential. Start, of course, by dividing both sides by 10: 3= lg(20/x). Assuming the your "lg" means natural logarithm, take exp of or "e" to the power of both sides. $e^3= \frac{20}{x}$. Can you solve it now?

3. Yes. I remember now. Thank you very much.