Khan Academy: Algebra: Systems of Three Variables

Put all that algebra learning to use! Using algebraic strategies, learners solve three-variable systems. They then use the three-variable systems to write a quadratic equation given three points on the parabola.

Sal uses the elimination method to simplify a system of three variables. Next, he employs the substitution method to check his solution. This resource would nicely complement any lesson on this topic.

This video demonstrates how to solve a system comprised of three equations in three variables using elimination. [7:00]

This video demonstrates how to solve systems of linear equations in two variables using the elimination method. There are three sample problems shown. [9:57]

How many different ways can three planes intersect? The interactive provides three movable planes. Pupils manipulate the planes to determine the number of solutions possible based upon their intersections.

Given a system of three linear equations, the student will solve the system with a unique solution.

This video demonstrates how to solve a word problem by setting and solving a system of linear inequalities. [8:09]

A video lesson that describes how any three non-collinear points actually define a circle. First it is shown that three points define a triangle. Then it is shown that the circumcenter of that triangle is actually the center of the...

This lesson video shows how to solve a system of three equations with three unknown.

This video demonstrates how to find the solution set for a system of three linear inequalities. [3:24]