# Thread: Help simplifying basic expression with e

1. ## Help simplifying basic expression with e

I have x/4 = lny This simplifies to y=e^(x-4)

Can someone help me understand the basic inverse properties of ln and e that would make x/(4 x ln)=y simplify to the answer above? Thanks.

2. ## Re: Help simplifying basic expression with e

Use the definition of the logarithm: $\ln(x)=y \Leftrightarrow e^{y}=x$

3. ## Re: Help simplifying basic expression with e

I'm not sure "simplify" is the right word.

You should have this property...The following Two statements are identical.

1) $log_{b}(a) = c$
2) $b^{c} = a$

For suitable a, b, and c.

How does this apply to your problem statement?

Revise: See, SIRON even called it a "Definition". It's not really a "simplify" thing.

4. ## Re: Help simplifying basic expression with e

I understand the two statements and the conversion you guys give, but I don't know how to apply them correctly to this problem.

5. ## Re: Help simplifying basic expression with e

You can say: $\frac{x}{4}=\ln(y) \Leftrightarrow e^{\frac{x}{4}}=y$

6. ## Re: Help simplifying basic expression with e

Originally Posted by benny92000
Can someone help me understand the basic inverse properties of ln and e that would make x/(4 x ln)=y simplify to the answer above? Thanks.
The natural log needs an argument and this has none. What is the question in full?

7. ## Re: Help simplifying basic expression with e

I don't remember the exact question. I understand it now. Thanks!