Problem with solving equation

Having trouble with a section in my summer assaignment, and my teacher doesnt respond to his e-mails... If someone could help with these few questions, it would help a lot. Thanks.

Solve for y in terms of t:

-2e^(-y/3)=t+4

-t/4)-ln3=ln(20-y)

I know for the 2nd question you need to combine to take the anti-log(I beleive), but I just dont know where. And I have no idea where to start on the first problem.

Re: Problem with solving equation

For the first one, take the of both sides so you get:

Now use the fact

Re: Problem with solving equation

You put a negative symbol before the (y/3). Could you tell me where you got that from?

Did you get it from the -2e from the begining and moved it to the exponent when you multiplied by the ln?

Also that would make -y/3 = (ln2e) X ((ln t+4))? e would have to be raised by somethig though, so I know that isnt right... but I'm hoping its something along those lines.

Re: Problem with solving equation

Sorry, I didn't see that. That's indeed a mistake. Indeed you get:

For the second one I would use the definition:

So in this case:

Re: Problem with solving equation

Ahh, that makes sense. Thank you so much.

Re: Problem with solving equation

You're welcome! :)

Notice you can simplify the second one:

Re: Problem with solving equation

That helps a lot! Thank you once again!