# Linear equations and functions

Contents

Linear equations like y = 2x + 7 are called "linear" because they make a straight line when we graph them. These tutorials introduce you to linear relationships, their graphs, and functions.

When you walk at a constant rate, the relationship between the distance you've walked and the time you've spent walking is proportional. In this tutorial, we learn about proportional relationships (constant rates) and their graphs..

Learn how to figure out if an ordered pair is a solution to a linear equation.

Relationships can be any association between sets of numbers while functions have only one output for a given input. This tutorial works through a bunch of examples of testing whether something is a valid function. As always, we really encourage you to pause the videos and try the problems before Sal does!
Common Core Standard: 8.F.A.1

Not every relationship in the universe can be represented by a line (in fact, most can't be). We call these "nonlinear". In this tutorial, you'll learn to tell the difference between a linear and nonlinear function!
Have fun!
Common Core Standare: 8.F.A.3