Your search for Inverse variation returned 3 hits:

Variation - Direct, Inverse & Joint
Direct & Inverse Variation: Two Variables
Joint Variation: Three or More Variables

When a word problem talks about two things being "proportional", this is what they're talking about. Or maybe they're "inversely proportional". "Joint" variation just refers to when you have three things that are proportional or inversely proportional instead of just the two, which is basically just ratios in disguise.

Part of the course(s): Middle School Math ,Pre-Algebra Class Page ,College Algebra ,Algebra

Direct & Inverse Variation: Two Variables

These two types of problems always involve two letters (usually x and y) and usually start the same way: if the problem has the words "varies directly" in it (or says two things are "proportional"), you just write down "y=kx" and start plug-and-chugging. If the problem says "varies inversely" (or variables are "inversely proportional"), you write down y=k/x and start plug-and-chugging. Sound too easy? What can I say: the same four steps will get you through every one of these things.

This video appears on the page: Variation – Joint & Inverse ,ACT Prep free videos ,free Accuplacer prep videos ,TCI free videos ,SAT Free Videos

Joint Variation: Three or More Variables

These problems are exactly like the problems in the previous video, except instead of 2 variables there are three or four. Either way, same series of steps! "Directly" will still mean multiply, and "inversely" will still mean divide, and "plug and chug" will still be in your future. CAUTION: this video won't make a ton of sense unless you watch the one before it, so I'd recommend that first.

This video appears on the page: Variation – Joint & Inverse
Having trouble finding what you're looking for? Check out this video.