# Thread: Did I solve this equation correctly?

1. ## Did I solve this equation correctly?

3e^0.085T = 30

My answer: T = 27.0894

My friend came up with 27.0892, so I'm curious to see who's wrong here. Or if we're both wrong.

2. Originally Posted by wrongnmbr
3e^0.085T = 30
My answer: T = 27.0894
My friend came up with 27.0892, so I'm curious to see who's wrong here. Or if we're both wrong.
Both wrong; how did you ever get that?

T = 30 / (3 * e^.085) = 9.18512.....

3. EDIT: Nevermind, I made a slip-up.

4. Do you know what is wrong with your posted question?
You do not understand how to post in correct symbols.
Why not learn to post in symbols? You can use LaTeX tags.
$$3e^{0.085T}=3$$ gives $3e^{0.085T}=3$.

Whereas $$3e^{0.085}T=3$$ gives $3e^{0.085}T=3$.

Which one do you mean? You cannot blame us for not being mind readers.

5. Originally Posted by wrongnmbr
3e^0.085T = 30

My answer: T = 27.0894
if you meant ...

$3e^{0.085t} = 30$

$e^{0.085t} = 10$

$0.085t = \ln(10)$

$\displaystyle t = \frac{\ln(10)}{0.085} = 27.0892...$

you owe your friend a beer.

6. Originally Posted by skeeter
if you meant ...

$3e^{0.085t} = 30$

$e^{0.085t} = 10$

$0.085t = \ln(10)$

$\displaystyle t = \frac{\ln(10)}{0.085} = 27.0892...$

you owe your friend a beer.
Lol, yeah, it's now been pointed out that I plugged it in my calculator incorrectly.