A Nice Olympiads Exponential Trick | How to solve for k ?

Hello, welcome to my KZbin channel.
As you enjoy watching my videos, please subscribe to my KZbin channel.
I upload Mathematics videos twice a day (10:00 GMT and 18:00 GMT)
Thank you so much for doing so.

[@anfractuousAlchemist]

FWIW, I would have noticed that 3 is a solution by inspection (or graphing :D) and then divided k^3 + k - 30 by (k -3) which gets you to the same place. I don't think there's really a difference between noticing the solution of 3 and you splitting the number up. As a tip for your channel, I don't think you should spend as much time on the trivial steps (adding 9 + 1 to get 10...)