I'm going through an examples section (on improper integrals) but I got lost at this bit:
$$\lim_{t\to-\infty} \frac{t}{e^{-t}} = \lim_{t\to-\infty}\frac{1}{-e^{-t}}.$$
I think it's a simple algebra trick but I don't see how the right hand side came to be. How did it become $1/-e^{-t}$?