First homework of the semester hits me with this:

Which of the following pairs of functions is a solution of the given system of differential equations on the interval

?

Select the correct answer.

I don't want the answer! I do notice that "e" is involved.

I tried setting each equation = to x or y to substitute...fail

I tired to solve for dt and substitue...fail

I tried "coupled diff eq", but due to 3 variables...fail

Lastly, tried to seperate the variables so that I could get a dx/x, but the dt variable kept tripping me up!

Please help... but no answer, I want to trounce this class!