The question is to prove the "k" in the following queston is equal to: k = 1/10Log_{e}(10/7)

and the original question is 70 = 100e^{-k10}

I'll show the steps i have used so far, but i don't understand the next step needed..

> 70/100 = e^{-k10 }> 7/10 = e^{-k10 }> log_{e}(7/10) = -k10

That is as far as i can get, if you know the next step please respond with the Log law that goes with it, Any help would be appreciated.

-Medusa