KhanAcademyVideos

Practice writing a system of linear equations that fits the constraints in a word problem.

Sal shows how to test whether or not a value is or isn't in the domain of a function.

Practice identifying the slope and y-intercept from a linear equation given in slope-intercept form — especially in equations that aren't obviously in slope-intercept form.

Given a linear relationship in a table, practice finding the slope and intercepts.

Given the graph of a discrete function, Sal shows how to evaluate the function for a few different values.

Practice determining what each of the slope, x-intercept, and y-intercept represent in a given linear relationship.

Practice writing a system of linear equations that fits the constraints in a word problem.

Practice determining which feature of a linear model (the slope, the x-intercept, or the y-intercept) is useful for answering a given question in context.

Given a linear relationship in a table, Sal graphs the relationship to explore what the slope and intercepts mean in the given context.

Given a written description of a linear relationship in a some context, write an equation that represents the linear relationship described.

Practice graphing a line given its slope and a point the line passes through.

Sal shows how to algebraically find the domain of a few different functions.

Given a graph of a system of equations and a context, practice interpreting what various points represent in that system.

Practice calculating the slope of a line given some points on the line shown in a table.

Clarifying standard form rules

Practice identifying strategies for eliminating variables in a system of equations.

How investing for capital formation can expand the production possibilities curve

The basis of the labor supply curve is the tradeoff of labor and leisure. When wages increase, the opportunity cost of leisure increases and people supply more labor. Interestingly, this is not always the case! At higher wages, the marginal benefit of higher wages becomes lower and when it drops below the marginal benefit of leisure, people switch to more leisure and less labor. This leads to the rather unusual looking backward bending labor supply curve.

The Sahara is the world's largest hot desert, spanning the entire northern part of Africa. Yet it hasn't always been dry -- archaeological and geological research shows that it has undergone major climatic changes over thousands of years. Rock art is one of the best records of the life of past peoples who lived across the Sahara. It often depicts extraordinary images of life, landscape and animals that show a time when the Sahara was much greener and wetter than it is now. To find out more, visit https://www.britishmuseum.org/africanrockart The African Rock Art Project is supported by Arcadia (https://www.arcadiafund.org.uk/) This film is in collaborative partnership with the Leverhulme Trust-funded project: “Peopling the Green Sahara. A multi-proxy approach to reconstructing the ecological and demographic history of the Saharan Holocene”, Paul Breeze, Nick Drake and Katie Manning, Department of Geography, King’s College London Modelling and mapping of the Green Sahara ©Kings College London Images ©Trust for African Rock Art (TARA)/David Coulson & ©Kings College London Animation and Motion Graphics by Soluis Heritage (http://www.soluis.com/)

Changes in interest rates in one country impact economic conditions in other countries. In this video, walk through a chain of events that starts with a change in interest rates in the United States that affects the relative value of the dollar, the Japanese Yen, and exports.