So, this is an assignment my friend and I have for our homework: $7 = 8 - 2e^{-3k}$
And the solution should be: $\frac{1}{3\ln(2)}$
But, I have no idea how they got there. I tried doing:
$\begin{align*} 7 &= 8 - 2e^{-3k}\\ 1 &= 2e^{-3k}\\ \frac{1}{2} &= e^{-3k} \end{align*}$
And now I don't know what to do next. Help!
PS: Neither of us was in school when they were learning this lesson. So, some description along the way will be greatly welcomed!