This is the biggest confusion my tutoring students have with Logs & Exponentials -- telling log graphs apart from exponential graphs, and knowing how to graph each -- so this video will probably help you too! (Hint: it will involve vertical asymptotes and horizontal asymptotes, and which goes with what.)
These super-hard word problems always involve people or machines working together to accomplish a task quicker, but in this video I show you a table trick to make them manageable. In one example, a couple of house painters - one who can paint a house in 3 days, the other 6 - work together to paint a house faster. In the others, we figure out how fast a hot and cold faucet can fill a tub.
If you do not have an account, you should get one, because it is awesome! You can save a playlist for each test or each chapter, and save your "greatest hits" into a "watch right before the final" list (not that we recommend cramming, but when in Rome...)