Linear equations & graphs

Heads up! This course may be archived and/or unavailable.

This course is a part of Algebra I, a 21-course Topic series from Khan Academy.

Learn about linear equations that contain two variables, and how these can be represented by graphical lines and tables of values.

This course contains 10 segments:

Two-variable linear equations intro

Understand what a solution to an equation really means. Practice plugging in values for variables to see whether or not an equation is true.

x-intercepts and y-intercepts

Learn about intercepts and practice finding them from graphs, tables, and equations.

Slope

Learn about slope (the steepness of a line) and how to find it.

Horizontal & vertical lines

You know what horizontal and vertical lines are, but how do their equations look? And what is their slope? Learn all about it in this tutorial.

Intro to slope-intercept form

Make an introduction with the most common form of linear equations, slope-intercept form! For example, y=3x+5 is a linear equation in slope-intercept form.

Graphing slope-intercept equations

Learn how to graph linear equations that are given in slope-intercept form. For example, graph y=2x+3.

Writing slope-intercept equations

Learn how to write the equation of a line (in slope-intercept form) when given the graph of the equation or two points on the line. For example, write the equation of the line that passes through the points (0,1) and (5,4).

Point-slope form

(y-b)=m(x-a)

Standard form

ax+by=c

Summary: Forms of two-variable linear equations

Take an overview of the three main forms of linear equations: slope-intercept, point-slope, and standard. Learn which form is most appropriate for different uses.