Thank you! I am self-studying and the precalculus textbook I am using gave one example. That one example was one I have seen before in Algebra textbooks and was very simple. I got to the exercises for the modeling section and found I was being thrown to the wolves. None of the exercises were as simple as the one example given. This video got me through the time distance problems in the modeling exercises.
The only thing I would suggest to add to this, would be to convert the hrs into minutes. Nobody says, "I ran for .6 hrs". They would say, "I ran for 36 minutes." The answers should be simplified to it's most practical form in order to make the user relate to the information better.
You can use algebra to find another formula for percent change: from (x-y)/y to x/y - 1 which is an easier formula to use in business conversations. The more difficult application is to determine when to use relative vs absolute change. Eg if your share of budget for gas spend is 50% this month vs 25% last month, what is more informative? That your share of gas spend went up 25pts or went up 100%?
Tables are THE unifying tool for word problems! I like to put double strokes into the columns where addition happens. See here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-t2KqV2jh0U0.html
How do you explain why you used the first column to solve for "t" and not the last column? I can see a student looking at the data in the last column and thinking that it would be just as easy to solve for "t" using that information.
Question: can you apply this to a business when it comes to projecting how long it would take to reach a certain amount of sales???... or apply this to any goal someone is trying to reach?? Just curious?
He wants his students to actually understand why they're doing what they're doing, not just how to plug numbers into a formula. Sure, it kinda drags if you already understand what he's talking about, but if this is new to you then it's a great introduction to the concept.
