yego.me
💡 Stop wasting time. Read Youtube instead of watch. Download Chrome Extension

Modeling with multiple variables: Pancakes | Modeling | Algebra || | Khan Academy


2m read
·Nov 10, 2024

We are told that Jade is making pancakes using flour, eggs, and milk. This table gives the cost per kilogram of each ingredient and the amount in kilograms that Jade uses. All right, the total amount Jade spends on ingredients is six dollars.

Write an equation that relates a, b, c, and d. Pause this video and see if you can have a go at this.

All right, now let's go through this together. So I like to do this in real time so that you can see my thought process. So I'm here with you right now.

So let's see. The total Jade spends, and this is going to be on flour, eggs, and milk, is going to be six dollars. One way to think about it is, and I'll do this in different colors, the flour dollars plus the eggs dollars, or the amount that Jade's going to spend on eggs, plus the amount that Jade spends on milk, I'll call that the milk dollars is going to be equal to the total amount, is going to be equal to six dollars.

So what's the total amount that Jade is going to spend on flour? Well, we can just look right over here: 0.9 dollars per kilogram times 8 kilograms. So Jade is going to spend 0.9 times 8 dollars. I'm just going to multiply these two things to figure out how much Jade spends on flour.

And so this is going to be equal to—I'll lose the dollar symbol just so we can focus on the numbers and the variables—0.9a. 0.9a, and this, of course, is going to be in dollars, which is important. I'm going to add dollars plus dollars plus dollars to get dollars.

Now, what about eggs? Well, the same notion: 0.2 kilograms times b dollars per kilogram. If I take the product of these two, I'm going to get 0.2b dollars, or I could just think of it as 0.2b if I don't write the dollar symbol.

And then last but not least, on milk, let me look at the product of these two things, of this and of this. So d kilograms at c dollars per kilogram, that's just going to be cd dollars.

So, plus cd, and all of that is going to be equal to six dollars. And we're done! We wrote an equation that relates a, b, c, and d.

More Articles

View All
Tax implications of non-typical pay structures | Employment | Financial Literacy | Khan Academy
So let’s think about some of the pros and cons of self-employment. I’m going to make a column of pros and then in cons maybe a nice scary red over here. Alright, cons. I think a lot of folks, when they imagine working for themselves, they imagine, “Well…
Environmental change and adaptation in Galápagos finches | Middle school biology | Khan Academy
This here is a picture of the ground finch of the Galapagos Islands, and one of its primary sources of food is seeds that it finds on the ground. If we go back to 1976, we can look at the distribution of beak depths, and these beak depths I would assume a…
Homeroom with Sal & Jonathan Haidt - Wednesday, July 1
Hi everyone! Welcome to our daily homeroom livestream. For those of you who are wondering what this is, this is something we started a few months ago. It’s really just a way to stay connected, have interesting conversations about education and other topic…
Safari Live - Day 269 | National Geographic
This program features live coverage of an African safari and may include animal kills and carcasses. Viewer discretion is advised. Hello, hello and good afternoon and welcome to the sunset Safari where I’ve got some very exciting news and I will tell you…
7 Principles for AI in Education: Part 1 of 2
So hello everyone, I’m Kristen Deso. I’m the chief learning officer at KH Academy. I want to lay the groundwork a little bit for why we’re here. The first part is because I’m sure all of you are bombarded by the messages around artificial intelligence. W…
Your Brain on Tech
[Music] Oh hello, technology isn’t just changing our lives; it’s changing our brains. Not just how they think, but how they look. It’s been shown that playing certain video games for hours can improve your memory for details, your ability to navigate spac…