Kahn Academy video - How to add and subtract fractions with like and unlike denominators.
In this video we explore how to derive the demand for a factor of production based on how productive that factor is and how much additional revenue that factor brings in. Created by Sal Khan.
To add the vectors (x₁,y₁) and (x₂,y₂), we add the corresponding components from each vector: (x₁+x₂,y₁+y₂). Here's a concrete example: the sum of (2,4) and (1,5) is (2+1,4+5), which is (3,9). There's also a nice graphical way to add vectors, and the two ways will always result in the same vector.
An introduction to probability through the example of flipping a quarter and rolling a die. it is a practice lesson.
Explore the mechanics of adjustable rate mortgages (ARM) in this video, including how they work and in what situation an ARM might be advantageous and when it might work against you.
Some advice from our storytellers.
More advice to new writers.
Advice on editing.
Advice for storytellers.
Advice from storytellers on structure.
Advice from our storytellers.
What affirmative action is in the United States and major legal cases and initiatives surrounding it. Coverage of Regents of the University of California v. Bakke, Grutter v. Bollinger, and Proposition 209 in California.
We've learned about demand for a good or service, but aggregate demand is different: its the demand for everything bought in an economy. In this video, we discuss how aggregate demand (AD) is different from demand and why aggregate demand is downward sloping. Created by Sal Khan.
Thinking about how we get Calories from the land limits human population densities. Created by Sal Khan.
Thinking about how we get Calories from the land limits human population densities. Created by Sal Khan.
How long of a runway does an A380 need? Created by Sal Khan.
Figuring how long it takes an A380 to take off given a constant acceleration. Created by Sal Khan.
Alcohol or ethanol fermentation, including yeast and its role in bread and wine production.
How did Alexander the Great take over Persia? Sal explains.
Alexander the Great takes power.